G.f.: sqrt( Sum_{n>=0} x^n / (1-x)^(4*n+1) * [Sum_{k=0..2*n} C(2*n,k)^2 * x^k]^2 ).
A246572
G.f.: sqrt( Sum_{n>=0} x^n / (1-x)^(4*n+1) * [Sum_{k=0..2*n} C(2*n,k)^2 * x^k]^2 ).
Terms
- a(0) =1a(1) =1a(2) =7a(3) =51a(4) =425a(5) =3879a(6) =36527a(7) =355333a(8) =3531175a(9) =35673875a(10) =365179885a(11) =3777991337a(12) =39430009247a(13) =414567124053
External references
- oeis: A246572