a(n) = 2^n*binomial(3*n,n)*(3*n+1).

A072975

a(n) = 2^n*binomial(3*n,n)*(3*n+1).

Terms

    a(0) =1a(1) =24a(2) =420a(3) =6720a(4) =102960a(5) =1537536a(6) =22573824a(7) =327444480a(8) =4707014400a(9) =67190323200a(10) =953748956160

External references