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 A320852 #4 Oct 22 2018 12:01:37 %S A320852 1,1,4,11,26,55,106,190,321,518,804,1207,1763,2511,3502,4794,6447, %T A320852 8541,11163,14407,18382,23215,29040,36005,44284,54059,65529,78918, %U A320852 94466,112434,133104,156783,183803,214518,249307,288580,332774,382358,437829,499717,568579 %N A320852 Number of 6-element subsets of [n] whose sum is a triangular number. %H A320852 Alois P. Heinz, <a href="/A320852/b320852.txt">Table of n, a(n) for n = 6..1000</a> %Y A320852 Column k=6 of A284249. %Y A320852 Cf. A000217. %K A320852 nonn %O A320852 6,3 %A A320852 _Alois P. Heinz_, Oct 22 2018