a(n) = binomial(n+3, 3)*8^n.

Terms

a(0) =1a(1) =32a(2) =640a(3) =10240a(4) =143360a(5) =1835008a(6) =22020096a(7) =251658240a(8) =2768240640a(9) =29527900160a(10) =307090161664