G.f.: Sum_{n>=0} x^n / (1-x)^(2*n+1) * [Sum_{k=0..n} C(n,k)^2 * x^k] * [Sum_{k=0..n} C(n,k)^2 * 2^k * x^k].
A243948
G.f.: Sum_{n>=0} x^n / (1-x)^(2*n+1) * [Sum_{k=0..n} C(n,k)^2 * x^k] * [Sum_{k=0..n} C(n,k)^2 * 2^k * x^k].
Terms
- a(0) =1a(1) =2a(2) =8a(3) =36a(4) =182a(5) =964a(6) =5296a(7) =29832a(8) =171238a(9) =997244a(10) =5874992a(11) =34937400a(12) =209392796a(13) =1263258760a(14) =7664233696a(15) =46726270992a(16) =286089651718
External references
- oeis: A243948