A290037 Number of set partitions of [n] having exactly eight blocks of size > 1.
2027025, 126351225, 4307428125, 106546244805, 2141473308975, 37150564425975, 577265949054795, 8235084928545475, 109751266389634870, 1384084804861708950, 16677998006092973550, 193476119789167365150, 2173729827868142994450, 23766456155164279406850
Offset: 16
Links
- Alois P. Heinz, Table of n, a(n) for n = 16..1000
- Wikipedia, Partition of a set
- Index entries for linear recurrences with constant coefficients, order 45.
Formula
E.g.f.: (exp(x)-x-1)^8/8!*exp(x).
a(0) = a(1) = 0, for n>1 a(n) = 9*a(n-1) + (n-1)*A290036(n-2). - Ray Chandler, Jul 21 2017