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Number of set partitions of [n] having exactly six pairs (m,m+1) such that m is in some block b and m+1 is in block b+1.
2

%I #5 Apr 14 2016 15:35:22

%S 0,1,28,416,4658,45095,404275,3485508,29543547,249503219,2117198929,

%T 18150345636,157763663783,1393693891866,12533041906408,

%U 114848421469811,1073139463501186,10228550424931925,99466689685460697,986879431951833062,9989549096908876766

%N Number of set partitions of [n] having exactly six 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="/A271793/b271793.txt">Table of n, a(n) for n = 6..300</a>

%e a(7) = 1: 1|2|3|4|5|6|7.

%e a(8) = 28: 12|3|4|5|6|7|8, 13|24|5|6|7|8, 1|23|4|5|6|7|8, 14|25|36|7|8, 1|24|35|6|7|8, 1|2|34|5|6|7|8, 15|26|37|48, 1|25|36|47|8, 1|2|35|46|7|8, 1|2|3|45|6|7|8, 16|27|38|4|5, 1|26|37|48|5, 1|2|36|47|58, 1|2|3|46|57|8, 1|2|3|4|56|7|8, 17|28|3|4|5|6, 1|27|38|4|5|6, 1|2|37|48|5|6, 1|2|3|47|58|6, 1|2|3|4|57|68, 1|2|3|4|5|67|8, 18|2|3|4|5|6|7, 1|28|3|4|5|6|7, 1|2|38|4|5|6|7, 1|2|3|48|5|6|7, 1|2|3|4|58|6|7, 1|2|3|4|5|68|7, 1|2|3|4|5|6|78.

%Y Column k=6 of A185982.

%K nonn

%O 6,3

%A _Alois P. Heinz_, Apr 14 2016