A363881 Number of partitions of [n] such that no block contains its size as an element.

1, 0, 0, 1, 3, 13, 50, 230, 1110, 5787, 32335, 191950, 1206247, 7997702, 55733468, 406952888, 3105706421, 24710573792, 204547052598, 1758110677909, 15663244043627, 144412976181189, 1375896762258868, 13528184875421816, 137098357090429007, 1430440534060723253

Offset

0,5

Links

Table of n, a(n) for n=0..25.

Wikipedia, Partition of a set

Example

a(0) = 1: () the empty partition.
a(3) = 1: 13|2.
a(4) = 3: 124|3, 13|2|4, 14|2|3.
a(5) = 13: 1235|4, 124|35, 124|3|5, 125|34, 125|3|4, 13|245, 13|2|45, 13|2|4|5, 145|2|3, 14|2|35, 14|2|3|5, 15|2|34, 15|2|3|4.
a(6) = 50: 12346|5, 1235|46, 1235|4|6, 1236|45, ..., 15|2|3|4|6, 16|2|35|4, 16|2|3|45, 16|2|3|4|5.

Crossrefs

Cf. A000110, A326493, A364277.

Sequence in context: A116427 A008827 A026529 * A357870 A286182 A101052

Adjacent sequences: A363878 A363879 A363880 * A363882 A363883 A363884

Keyword

nonn

Author

Alois P. Heinz, Jul 17 2023

Status

approved