G.f.: Sum_{n>=0} x^n / (1-4*x)^(2*n+1) * [Sum_{k=0..n} C(n,k)^2 * 2^k * x^k] * [Sum_{k=0..n} C(n,k)^2 * 4^k * x^k].
A248053
G.f.: Sum_{n>=0} x^n / (1-4*x)^(2*n+1) * [Sum_{k=0..n} C(n,k)^2 * 2^k * x^k] * [Sum_{k=0..n} C(n,k)^2 * 4^k * x^k].
Terms
- a(0) =1a(1) =5a(2) =35a(3) =285a(4) =2519a(5) =23545a(6) =228715a(7) =2284365a(8) =23294551a(9) =241366025a(10) =2532599675a(11) =26845322925a(12) =286946021495
External references
- oeis: A248053