a(n) = multinomial(3*n+2; 2, 3, 3, ..., 3) (n times '3').

A327412

a(n) = multinomial(3*n+2; 2, 3, 3, ..., 3) (n times '3').

Terms

    a(0) =1a(1) =10a(2) =560a(3) =92400a(4) =33633600a(5) =22870848000

External references