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

A378780

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

Terms

    a(0) =0a(1) =6a(2) =120a(3) =2016a(4) =31680a(5) =480480a(6) =7128576a(7) =104186880a(8) =1506244608a(9) =21596889600a(10) =307660953600

External references