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 A275291 #8 Aug 02 2016 08:05:12 %S A275291 1,4,50,250,2160,12256,91925,559987,3939653,24964844,170468820, %T A275291 1104449861,7440709045,48835462696,327230257098,2164985118201, %U A275291 14485751773693,96353703793654,644984901718337,4306885857654070,28868100135841407,193352040530826181 %N A275291 Number of set partitions of [n] with symmetric block size list of length seven. %H A275291 Alois P. Heinz, <a href="/A275291/b275291.txt">Table of n, a(n) for n = 7..500</a> %H A275291 Wikipedia, <a href="https://en.wikipedia.org/wiki/Partition_of_a_set">Partition of a set</a> %F A275291 a(n) ~ 7^(n+1/2) / (5760*Pi^(3/2)*n^(3/2)). - _Vaclav Kotesovec_, Aug 02 2016 %e A275291 a(8) = 4: 1|2|3|45|6|7|8, 1|2|3|46|5|7|8, 1|2|3|47|5|6|8, 1|2|3|48|5|6|7. %Y A275291 Column k=7 of A275281. %K A275291 nonn %O A275291 7,2 %A A275291 _Alois P. Heinz_, Jul 22 2016