This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A320853 #4 Oct 22 2018 12:02:11 %S A320853 1,1,5,14,36,84,174,337,613,1058,1749,2787,4304,6463,9476,13598,19140, %T A320853 26486,36079,48461,64263,84209,109160,140100,178144,224578,280871, %U A320853 348655,429780,526341,640642,775262,933082,1117259,1331289,1579031,1864697,2192905 %N A320853 Number of 7-element subsets of [n] whose sum is a triangular number. %H A320853 Alois P. Heinz, <a href="/A320853/b320853.txt">Table of n, a(n) for n = 7..1000</a> %Y A320853 Column k=7 of A284249. %Y A320853 Cf. A000217. %K A320853 nonn %O A320853 7,3 %A A320853 _Alois P. Heinz_, Oct 22 2018