a(n) = (3*n+1)*a(n-1) - a(n-2), starting a(0)=0, a(1)=1.

A121351

a(n) = (3*n+1)*a(n-1) - a(n-2), starting a(0)=0, a(1)=1.

Terms

    a(0) =0a(1) =1a(2) =7a(3) =69a(4) =890a(5) =14171a(6) =268359a(7) =5889727a(8) =146974816a(9) =4109405121a(10) =127244583935

External references