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 A270956 #5 Mar 27 2016 14:26:03 %S A270956 3,27,159,857,4726,27385,167097,1071422,7203162,50674005,372321574, %T A270956 2851766861,22729523020,188191920799,1616005571254,14370046950779, %U A270956 132139869946194,1254871372262202,12292010800020819,124053806137088093,1288543305931949964 %N A270956 Number of set partitions of [n] having exactly two pairs (m,m+1) such that m+1 is in some block b and m is in block b+1. %H A270956 Alois P. Heinz, <a href="/A270956/b270956.txt">Table of n, a(n) for n = 5..220</a> %H A270956 Wikipedia, <a href="https://en.wikipedia.org/wiki/Partition_of_a_set">Partition of a set</a> %e A270956 a(5) = 3: 135|24, 13|25|4, 15|24|3. %e A270956 a(6) = 27: 1246|35, 124|36|5, 126|35|4, 1346|25, 134|26|5, 1356|24, 135|246, 135|24|6, 136|245, 13|246|5, 13|256|4, 13|25|46, 13|25|4|6, 13|26|45, 13|2|46|5, 146|235, 14|236|5, 16|235|4, 156|24|3, 15|246|3, 15|24|36, 15|24|3|6, 16|245|3, 1|246|35, 1|24|36|5, 16|25|34, 1|26|35|4. %Y A270956 Column k=2 of A270953. %K A270956 nonn %O A270956 5,1 %A A270956 _Alois P. Heinz_, Mar 26 2016