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 A287254 #6 May 22 2017 11:48:45 %S A287254 1,1,2,5,15,52,202,857,3933,19373,101755,566712,3331349,20592862, %T A287254 133439286,903926271,6385918342,46950260915,358560107124, %U A287254 2839638581291,23285101241537,197425160416845,1728548417051752,15610025975013920,145242705457704688 %N A287254 Number of set partitions of [n] such that all absolute differences between least elements of consecutive blocks are <= four. %H A287254 Alois P. Heinz, <a href="/A287254/b287254.txt">Table of n, a(n) for n = 0..584</a> %H A287254 Wikipedia, <a href="https://en.wikipedia.org/wiki/Partition_of_a_set">Partition of a set</a> %F A287254 a(n) = A287216(n,4). %F A287254 a(n) = A000110(n) for n <= 5. %Y A287254 Column k=4 of A287216. %Y A287254 Cf. A000110. %K A287254 nonn %O A287254 0,3 %A A287254 _Alois P. Heinz_, May 22 2017