A271792 Number of set partitions of [n] having exactly five pairs (m,m+1) such that m is in some block b and m+1 is in block b+1.

0, 1, 21, 242, 2161, 17081, 127540, 931343, 6781012, 49778592, 370879817, 2815885116, 21840126520, 173297901709, 1407962621143, 11717253906772, 99896499620107, 872434202618833, 7803398795633086, 71462039680103117, 669812596793753200, 6423126853283399476

Offset

5,3

Links

Alois P. Heinz, Table of n, a(n) for n = 5..300

Example

a(6) = 1: 1|2|3|4|5|6.
a(7) = 21: 12|3|4|5|6|7, 13|24|5|6|7, 1|23|4|5|6|7, 14|25|36|7, 1|24|35|6|7, 1|2|34|5|6|7, 15|26|37|4, 1|25|36|47, 1|2|35|46|7, 1|2|3|45|6|7, 16|27|3|4|5, 1|26|37|4|5, 1|2|36|47|5, 1|2|3|46|57, 1|2|3|4|56|7, 17|2|3|4|5|6, 1|27|3|4|5|6, 1|2|37|4|5|6, 1|2|3|47|5|6, 1|2|3|4|57|6, 1|2|3|4|5|67.

Crossrefs

Column k=5 of A185982.

Sequence in context: A089937 A175843 A198974 * A177730 A199300 A302992

Adjacent sequences: A271789 A271790 A271791 * A271793 A271794 A271795

Keyword

nonn

Author

Alois P. Heinz, Apr 14 2016

Status

approved