a(n) = (3/4) * Sum_{k>=0} (3*k)^n/4^k.
A255927
a(n) = (3/4) * Sum_{k>=0} (3*k)^n/4^k.
Terms
- a(0) =1a(1) =1a(2) =5a(3) =33a(4) =285a(5) =3081a(6) =40005a(7) =606033a(8) =10491885a(9) =204343641a(10) =4422082005a(11) =105265315233
External references
- oeis: A255927