G.f.: sqrt( 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 ).
A246573
G.f.: sqrt( 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) =3a(2) =15a(3) =125a(4) =1033a(5) =9385a(6) =88531a(7) =858739a(8) =8517503a(9) =85867417a(10) =877145957a(11) =9056393207a(12) =94337137375a(13) =990036525507
External references
- oeis: A246573