A276728 Number of set partitions of [2n] where k=n is minimal such that for each block b the smallest integer interval containing b has at most k elements.

1, 1, 4, 29, 336, 5375, 111138, 2845864, 87597223, 3170429794, 132647186513, 6328769607152, 340517379645028, 20469645334387763, 1363935094328964210, 100052662656438620359, 8032243625863280744704

Offset

0,3

Links

Table of n, a(n) for n=0..16.

Formula

a(n) = A276727(2n,n).

Example

a(1) = 1: 1|2.
a(2) = 4: 12|34, 12|3|4, 1|23|4, 1|2|34.
a(3) = 29: 123|456, 123|45|6, 123|46|5, 123|4|56, 123|4|5|6, 12|345|6, 12|35|46, 12|35|4|6, 12|3|456, 12|3|46|5, 13|24|56, 13|24|5|6, 13|2|456, 13|2|45|6, 13|2|46|5, 13|2|4|56, 13|2|4|5|6, 1|234|56, 1|234|5|6, 1|23|456, 1|23|46|5, 1|24|35|6, 1|24|3|56, 1|24|3|5|6, 1|2|345|6, 1|2|35|46, 1|2|35|4|6, 1|2|3|456, 1|2|3|46|5.

Crossrefs

Cf. A276727, A276892.

Sequence in context: A325478 A099700 A305636 * A256006 A137646 A231498

Adjacent sequences: A276725 A276726 A276727 * A276729 A276730 A276731

Keyword

nonn

Author

Alois P. Heinz, Sep 16 2016

Status

approved