a(n) = 2*Sum_{k odd} k!*Stirling2(n,k)/(k + 1).

A281817

a(n) = 2*Sum_{k odd} k!*Stirling2(n,k)/(k + 1).

Terms

    a(0) =0a(1) =1a(2) =1a(3) =4a(4) =19a(5) =116a(6) =871a(7) =7764a(8) =80179a(9) =941812a(10) =12403711a(11) =181056404a(12) =2901669739a(13) =50656307508a(14) =956922611191

External references