A271753 Number of set partitions of [n+2] such that n is the largest element of the last block.

0, 1, 6, 29, 139, 692, 3627, 20085, 117488, 724731, 4703699, 32043002, 228572813, 1703454469, 13235230990, 106997762361, 898404819935, 7821618182572, 70498093658879, 656892909516441, 6319385054660256, 62688326727955007, 640525850674446471, 6733883466256420010

Offset

1,3

Links

Alois P. Heinz, Table of n, a(n) for n = 1..575

Wikipedia, Partition of a set

Formula

a(n) = A271466(n+2,n).

Example

a(3) = 6: 1245|3, 145|23, 145|2|3, 14|25|3, 15|24|3, 1|245|3.
a(4) = 29: 12356|4, 1256|34, 1256|3|4, 125|36|4, 126|35|4, 12|356|4, 1356|24, 1356|2|4, 135|26|4, 136|25|4, 13|256|4, 156|234, 156|23|4, 15|236|4, 16|235|4, 1|2356|4, 156|2|34, 15|26|34, 16|25|34, 1|256|34, 156|2|3|4, 15|26|3|4, 15|2|36|4, 16|25|3|4, 1|256|3|4, 1|25|36|4, 16|2|35|4, 1|26|35|4, 1|2|356|4.

Crossrefs

A diagonal of A271466.

Sequence in context: A359920 A110311 A030221 * A367469 A009153 A012325

Adjacent sequences: A271750 A271751 A271752 * A271754 A271755 A271756

Keyword

nonn

Author

Alois P. Heinz, Apr 13 2016

Status

approved