A275292 Number of set partitions of [n] with symmetric block size list of length nine.

1, 5, 95, 575, 7175, 49091, 513206, 3800358, 36298007, 282835456, 2571177913, 20702222482, 183079272792, 1505743012484, 13114463722858, 109381638489849, 944974537003694, 7956650229728706, 68468581589476475, 580345660548809882, 4986413617279183229

Offset: 9

Author

Alois P. Heinz, Jul 22 2016

Keywords

• nonn

Examples

			a(10) = 5: 1|2|3|4|56|7|8|9|(10), 1|2|3|4|57|6|8|9|(10), 1|2|3|4|58|6|7|9|(10), 1|2|3|4|59|6|7|8|(10), 1|2|3|4|5(10)|6|7|8|9.
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 9..500
• Wikipedia, Partition of a set

Crossrefs

Column k=9 of A275281.

Formula

a(n) ~ 9^n / (71680*Pi^2*n^2). - Vaclav Kotesovec, Aug 02 2016