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 A272433 #4 May 01 2016 12:23:14
%S A272433 1,1,1,7,9,31,403,757,2873,12607,333051,761377,3699435,16383121,
%T A272433 108710085,4855474267,13594184793,76375572751,388660153867,
%U A272433 2504206435681,20148774553859,1556349601444477,10470804739432665,113472934257201031,1621680033815396315
%N A272433 Number of ordered set partitions of {1,2,...,n} such that no part has the same size as any of its five immediate predecessors.
%H A272433 Alois P. Heinz, <a href="/A272433/b272433.txt">Table of n, a(n) for n = 0..60</a>
%Y A272433 Column k=5 of A261959.
%K A272433 nonn
%O A272433 0,4
%A A272433 _Alois P. Heinz_, Apr 29 2016