G.f.: Sum_{n>=0} 4^n * x^n / (1-x)^(2*n+1) * [Sum_{k=0..n} C(n,k)^2 * x^k]^2.
A246540
G.f.: Sum_{n>=0} 4^n * x^n / (1-x)^(2*n+1) * [Sum_{k=0..n} C(n,k)^2 * x^k]^2.
Terms
- a(0) =1a(1) =5a(2) =37a(3) =325a(4) =3125a(5) =31925a(6) =339077a(7) =3700645a(8) =41200981a(9) =465736725a(10) =5328229797a(11) =61552244485a(12) =716791570549
External references
- oeis: A246540