a(n) = [x^n] Product_{k=1..n} 1/(x^(2*k)*(1-x^k)^2).
A258793
a(n) = [x^n] Product_{k=1..n} 1/(x^(2*k)*(1-x^k)^2).
Terms
- a(0) =1a(1) =4a(2) =55a(3) =896a(4) =16494a(5) =326422a(6) =6812064a(7) =147937628a(8) =3315019979a(9) =76184664934
External references
- oeis: A258793