G.f.: exp( Sum_{n>=1} A007837(n)*x^n/n ), where A007837(n) = number of partitions of n-set with distinct block sizes.

A168268

G.f.: exp( Sum_{n>=1} A007837(n)*x^n/n ), where A007837(n) = number of partitions of n-set with distinct block sizes.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =2a(4) =3a(5) =6a(6) =20a(7) =45a(8) =116a(9) =385a(10) =2224a(11) =6396a(12) =23708a(13) =88065a(14) =445784a(15) =3962502a(16) =14478825a(17) =64495508a(18) =309085415a(19) =1608099881a(20) =10856426344a(21) =142802148953a(22) =604464533847

External references