G.f.: Sum_{n>=0} x^n / (1-x)^(4*n+3) * [Sum_{k=0..2*n+1} C(2*n+1,k)^2 * x^k]^2.
A246571
G.f.: Sum_{n>=0} x^n / (1-x)^(4*n+3) * [Sum_{k=0..2*n+1} C(2*n+1,k)^2 * x^k]^2.
Terms
- a(0) =1a(1) =6a(2) =39a(3) =340a(4) =3041a(5) =28718a(6) =279987a(7) =2788464a(8) =28256709a(9) =290124182a(10) =3010689527a(11) =31516942060a(12) =332347297141
External references
- oeis: A246571