a(n) = n! * [x^n] 1/(1 - 4*x)^(n/4).

A303487

a(n) = n! * [x^n] 1/(1 - 4*x)^(n/4).

Terms

    a(0) =1a(1) =1a(2) =12a(3) =231a(4) =6144a(5) =208845a(6) =8648640a(7) =422463195a(8) =23781703680

External references