a(n) = (n+2)*a(n-1) + a(n-2), with a(0)=0, a(1)=1.
A058308
a(n) = (n+2)*a(n-1) + a(n-2), with a(0)=0, a(1)=1.
Terms
- a(0) =0a(1) =1a(2) =4a(3) =21a(4) =130a(5) =931a(6) =7578a(7) =69133a(8) =698908a(9) =7757121a(10) =93784360a(11) =1226953801a(12) =17271137574a(13) =260294017411
External references
- oeis: A058308