a(n) = A000108(n)*(A000142(n+1)-1).

A089833

a(n) = A000108(n)*(A000142(n+1)-1).

Terms

    a(0) =0a(1) =1a(2) =10a(3) =115a(4) =1666a(5) =30198a(6) =665148a(7) =17296851a(8) =518916970a(9) =17643220738a(10) =670442556004

External references