A271793 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.

0, 1, 28, 416, 4658, 45095, 404275, 3485508, 29543547, 249503219, 2117198929, 18150345636, 157763663783, 1393693891866, 12533041906408, 114848421469811, 1073139463501186, 10228550424931925, 99466689685460697, 986879431951833062, 9989549096908876766

Offset

6,3

Links

Alois P. Heinz, Table of n, a(n) for n = 6..300

Example

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

Crossrefs

Column k=6 of A185982.

Sequence in context: A238600 A278009 A233333 * A024213 A004415 A096949

Adjacent sequences: A271790 A271791 A271792 * A271794 A271795 A271796

Keyword

nonn

Author

Alois P. Heinz, Apr 14 2016

Status

approved