A271467 Number of set partitions of [2n] such that n is the largest element of the last block.

0, 1, 10, 149, 3149, 88772, 3195161, 142084077, 7611839904, 481614364251, 35417157810681, 2987457716884346, 285867917955683723, 30741794345071162069, 3685435185993122202106, 489101076818110701758097, 71414666988339306082779537, 11410190978037926887950636172

Offset: 1

Author

Alois P. Heinz, Apr 08 2016

Keywords

• nonn

Comments

Each set partition is written as a sequence of blocks, ordered by the smallest elements in the blocks.

Examples

			a(2) = 1: 134|2.
a(3) = 10: 12456|3, 1456|23, 1456|2|3, 145|26|3, 146|25|3, 14|256|3, 156|24|3, 15|246|3, 16|245|3, 1|2456|3.
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..200
• Wikipedia, Partition of a set

Crossrefs

Cf. A271466.

Formula

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