%I #5 Apr 14 2016 11:50:54
%S 0,1,6,24,86,307,1143,4513,18956,84546,399218,1989792,10439521,
%T 57504306,331747730,1999924893,12571830681,82245682149,558951842996,
%U 3939679356783,28754596249395,217019729585609,1691485555633721,13598390501982510,112633410446366669
%N Number of set partitions of [n] having exactly two pairs (m,m+1) such that m is in some block b and m+1 is in block b+1.
%H Alois P. Heinz, <a href="/A271789/b271789.txt">Table of n, a(n) for n = 2..400</a>
%e a(3) = 1: 1|2|3.
%e a(4) = 6: 12|3|4, 13|24, 1|23|4, 14|2|3, 1|24|3, 1|2|34.
%e a(5) = 24: 123|4|5, 124|35, 12|34|5, 125|3|4, 12|35|4, 12|3|45, 134|25, 135|24, 13|245, 13|2|4|5, 14|235, 1|234|5, 15|23|4, 1|235|4, 1|23|45, 145|2|3, 14|2|35, 14|2|3|5, 15|24|3, 1|245|3, 1|24|3|5, 15|2|34, 1|25|34, 1|2|345.
%Y Column k=2 of A185982.
%K nonn
%O 2,3
%A _Alois P. Heinz_, Apr 14 2016