{"group":{"id":1,"name":"Community","lockable":false,"created_at":"2012-01-18T18:02:15.000Z","updated_at":"2026-05-26T00:16:20.000Z","description":"Problems submitted by members of the MATLAB Central community.","is_default":true,"created_by":161519,"badge_id":null,"featured":false,"trending":false,"solution_count_in_trending_period":0,"trending_last_calculated":"2026-05-26T00:00:00.000Z","image_id":null,"published":true,"community_created":false,"status_id":2,"is_default_group_for_player":false,"deleted_by":null,"deleted_at":null,"restored_by":null,"restored_at":null,"description_opc":null,"description_html":null,"published_at":null},"problems":[{"id":44732,"title":"Highly divisible triangular number (inspired by Project Euler 12)","description":"Triangular numbers can be calculated by the sum from 1 to n. For example, the first 10 triangular numbers are:\r\n\r\n 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, ...\r\n\r\nAll divisors for each of these numbers are listed below\r\n\r\n 1: 1\r\n 3: 1,3\r\n 6: 1,2,3,6\r\n 10: 1,2,5,10\r\n 15: 1,3,5,15\r\n 21: 1,3,7,21\r\n 28: 1,2,4,7,14,28\r\n 36: 1,2,3,4,6,9,12,18,36\r\n 45: 1,3,5,9,15,45\r\n 55: 1,5,11,55\r\n\r\nYour challenge is to write a function that will return the value of the first triangular number to have over d divisors (d will be passed to your function).","description_html":"\u003cp\u003eTriangular numbers can be calculated by the sum from 1 to n. For example, the first 10 triangular numbers are:\u003c/p\u003e\u003cpre\u003e 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, ...\u003c/pre\u003e\u003cp\u003eAll divisors for each of these numbers are listed below\u003c/p\u003e\u003cpre\u003e 1: 1\r\n 3: 1,3\r\n 6: 1,2,3,6\r\n 10: 1,2,5,10\r\n 15: 1,3,5,15\r\n 21: 1,3,7,21\r\n 28: 1,2,4,7,14,28\r\n 36: 1,2,3,4,6,9,12,18,36\r\n 45: 1,3,5,9,15,45\r\n 55: 1,5,11,55\u003c/pre\u003e\u003cp\u003eYour challenge is to write a function that will return the value of the first triangular number to have over d divisors (d will be passed to your function).\u003c/p\u003e","function_template":"function y = div_tri_n(d)\r\n y = d;\r\nend","test_suite":"%%\r\nassessFunctionAbsence({'regexp', 'regexpi', 'str2num'},'FileName','div_tri_n.m')\r\n\r\n%%\r\nassert(isequal(div_tri_n(2),6))\r\n\r\n%%\r\nassert(isequal(div_tri_n(4),28))\r\n\r\n%%\r\nassert(isequal(div_tri_n(8),36))\r\n\r\n%%\r\nassert(isequal(div_tri_n(10),120))\r\n\r\n%%\r\nassert(isequal(div_tri_n(20),630))\r\n\r\n%%\r\nassert(isequal(div_tri_n(25),2016))\r\n\r\n%%\r\nassert(isequal(div_tri_n(39),3240))\r\n\r\n%%\r\nassert(isequal(div_tri_n(40),5460))\r\n\r\n%%\r\nassert(isequal(div_tri_n(50),25200))\r\n\r\n%%\r\nassert(isequal(div_tri_n(70),25200))\r\n\r\n%%\r\nassert(isequal(div_tri_n(80),25200))\r\n\r\n%%\r\nassert(isequal(div_tri_n(100),73920))\r\n\r\n%%\r\nassert(isequal(div_tri_n(115),157080))\r\n\r\n%%\r\nassert(isequal(div_tri_n(120),157080))\r\n\r\n%%\r\nassert(isequal(div_tri_n(130),437580))","published":true,"deleted":false,"likes_count":2,"comments_count":1,"created_by":26769,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":167,"test_suite_updated_at":"2018-08-20T16:04:49.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2018-08-20T15:15:06.000Z","updated_at":"2026-05-22T15:44:34.000Z","published_at":"2018-08-20T16:04:49.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eTriangular numbers can be calculated by the sum from 1 to n. For example, the first 10 triangular numbers are:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, ...]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eAll divisors for each of these numbers are listed below\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ 1: 1\\n 3: 1,3\\n 6: 1,2,3,6\\n 10: 1,2,5,10\\n 15: 1,3,5,15\\n 21: 1,3,7,21\\n 28: 1,2,4,7,14,28\\n 36: 1,2,3,4,6,9,12,18,36\\n 45: 1,3,5,9,15,45\\n 55: 1,5,11,55]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eYour challenge is to write a function that will return the value of the first triangular number to have over d divisors (d will be passed to your function).\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"}],"problem_search":{"problems":[{"id":44732,"title":"Highly divisible triangular number (inspired by Project Euler 12)","description":"Triangular numbers can be calculated by the sum from 1 to n. For example, the first 10 triangular numbers are:\r\n\r\n 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, ...\r\n\r\nAll divisors for each of these numbers are listed below\r\n\r\n 1: 1\r\n 3: 1,3\r\n 6: 1,2,3,6\r\n 10: 1,2,5,10\r\n 15: 1,3,5,15\r\n 21: 1,3,7,21\r\n 28: 1,2,4,7,14,28\r\n 36: 1,2,3,4,6,9,12,18,36\r\n 45: 1,3,5,9,15,45\r\n 55: 1,5,11,55\r\n\r\nYour challenge is to write a function that will return the value of the first triangular number to have over d divisors (d will be passed to your function).","description_html":"\u003cp\u003eTriangular numbers can be calculated by the sum from 1 to n. For example, the first 10 triangular numbers are:\u003c/p\u003e\u003cpre\u003e 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, ...\u003c/pre\u003e\u003cp\u003eAll divisors for each of these numbers are listed below\u003c/p\u003e\u003cpre\u003e 1: 1\r\n 3: 1,3\r\n 6: 1,2,3,6\r\n 10: 1,2,5,10\r\n 15: 1,3,5,15\r\n 21: 1,3,7,21\r\n 28: 1,2,4,7,14,28\r\n 36: 1,2,3,4,6,9,12,18,36\r\n 45: 1,3,5,9,15,45\r\n 55: 1,5,11,55\u003c/pre\u003e\u003cp\u003eYour challenge is to write a function that will return the value of the first triangular number to have over d divisors (d will be passed to your function).\u003c/p\u003e","function_template":"function y = div_tri_n(d)\r\n y = d;\r\nend","test_suite":"%%\r\nassessFunctionAbsence({'regexp', 'regexpi', 'str2num'},'FileName','div_tri_n.m')\r\n\r\n%%\r\nassert(isequal(div_tri_n(2),6))\r\n\r\n%%\r\nassert(isequal(div_tri_n(4),28))\r\n\r\n%%\r\nassert(isequal(div_tri_n(8),36))\r\n\r\n%%\r\nassert(isequal(div_tri_n(10),120))\r\n\r\n%%\r\nassert(isequal(div_tri_n(20),630))\r\n\r\n%%\r\nassert(isequal(div_tri_n(25),2016))\r\n\r\n%%\r\nassert(isequal(div_tri_n(39),3240))\r\n\r\n%%\r\nassert(isequal(div_tri_n(40),5460))\r\n\r\n%%\r\nassert(isequal(div_tri_n(50),25200))\r\n\r\n%%\r\nassert(isequal(div_tri_n(70),25200))\r\n\r\n%%\r\nassert(isequal(div_tri_n(80),25200))\r\n\r\n%%\r\nassert(isequal(div_tri_n(100),73920))\r\n\r\n%%\r\nassert(isequal(div_tri_n(115),157080))\r\n\r\n%%\r\nassert(isequal(div_tri_n(120),157080))\r\n\r\n%%\r\nassert(isequal(div_tri_n(130),437580))","published":true,"deleted":false,"likes_count":2,"comments_count":1,"created_by":26769,"edited_by":null,"edited_at":null,"deleted_by":null,"deleted_at":null,"solvers_count":167,"test_suite_updated_at":"2018-08-20T16:04:49.000Z","rescore_all_solutions":false,"group_id":1,"created_at":"2018-08-20T15:15:06.000Z","updated_at":"2026-05-22T15:44:34.000Z","published_at":"2018-08-20T16:04:49.000Z","restored_at":null,"restored_by":null,"spam":false,"simulink":false,"admin_reviewed":false,"description_opc":"{\"relationships\":[{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/document\",\"targetMode\":\"\",\"relationshipId\":\"rId1\",\"target\":\"/matlab/document.xml\"},{\"relationshipType\":\"http://schemas.mathworks.com/matlab/code/2013/relationships/output\",\"targetMode\":\"\",\"relationshipId\":\"rId2\",\"target\":\"/matlab/output.xml\"}],\"parts\":[{\"partUri\":\"/matlab/document.xml\",\"relationship\":[],\"contentType\":\"application/vnd.mathworks.matlab.code.document+xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\"?\u003e\\n\u003cw:document xmlns:w=\\\"http://schemas.openxmlformats.org/wordprocessingml/2006/main\\\"\u003e\u003cw:body\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eTriangular numbers can be calculated by the sum from 1 to n. For example, the first 10 triangular numbers are:\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, ...]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eAll divisors for each of these numbers are listed below\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"code\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003e\u003c![CDATA[ 1: 1\\n 3: 1,3\\n 6: 1,2,3,6\\n 10: 1,2,5,10\\n 15: 1,3,5,15\\n 21: 1,3,7,21\\n 28: 1,2,4,7,14,28\\n 36: 1,2,3,4,6,9,12,18,36\\n 45: 1,3,5,9,15,45\\n 55: 1,5,11,55]]\u003e\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003cw:p\u003e\u003cw:pPr\u003e\u003cw:pStyle w:val=\\\"text\\\"/\u003e\u003c/w:pPr\u003e\u003cw:r\u003e\u003cw:t\u003eYour challenge is to write a function that will return the value of the first triangular number to have over d divisors (d will be passed to your function).\u003c/w:t\u003e\u003c/w:r\u003e\u003c/w:p\u003e\u003c/w:body\u003e\u003c/w:document\u003e\"},{\"partUri\":\"/matlab/output.xml\",\"contentType\":\"text/xml\",\"content\":\"\u003c?xml version=\\\"1.0\\\" encoding=\\\"UTF-8\\\" standalone=\\\"no\\\" ?\u003e\u003cembeddedOutputs\u003e\u003cmetaData\u003e\u003cevaluationState\u003emanual\u003c/evaluationState\u003e\u003clayoutState\u003ecode\u003c/layoutState\u003e\u003coutputStatus\u003eready\u003c/outputStatus\u003e\u003c/metaData\u003e\u003coutputArray type=\\\"array\\\"/\u003e\u003cregionArray type=\\\"array\\\"/\u003e\u003c/embeddedOutputs\u003e\"}]}"}],"errors":[],"facets":[[{"value":"Project Euler II","count":1,"selected":false}],[{"value":"medium","count":1,"selected":false}]],"term":"tag:\"triangular number\"","page":1,"per_page":50,"sort":"map(difficulty_value,0,0,999) asc"}}