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 A271755 #5 Apr 13 2016 15:01:36 %S A271755 0,1,18,149,1039,6932,46299,315597,2215148,16075611,120829511, %T A271755 941052026,7592454845,63417026389,547926762922,4892438131137, %U A271755 45101313988931,428831073340204,4201412824028351,42374784500354529,439570765566102348,4685781221854745135 %N A271755 Number of set partitions of [n+4] such that n is the largest element of the last block. %H A271755 Alois P. Heinz, <a href="/A271755/b271755.txt">Table of n, a(n) for n = 1..573</a> %H A271755 Wikipedia, <a href="https://en.wikipedia.org/wiki/Partition_of_a_set">Partition of a set</a> %F A271755 a(n) = A271466(n+4,n). %e A271755 a(3) = 18: 124567|3, 14567|23, 14567|2|3, 1456|27|3, 1457|26|3, 145|267|3, 1467|25|3, 146|257|3, 147|256|3, 14|2567|3, 1567|24|3, 156|247|3, 157|246|3, 15|2467|3, 167|245|3, 16|2457|3, 17|2456|3, 1|24567|3. %Y A271755 A diagonal of A271466. %K A271755 nonn %O A271755 1,3 %A A271755 _Alois P. Heinz_, Apr 13 2016