a(n) = n*(n+1)*(n+2)*a(n-1)/6 for n >= 1; a(0) = 1.

A087047

a(n) = n*(n+1)*(n+2)*a(n-1)/6 for n >= 1; a(0) = 1.

Terms

    a(0) =1a(1) =1a(2) =4a(3) =40a(4) =800a(5) =28000a(6) =1568000a(7) =131712000a(8) =15805440000

External references