G.f.: Sum_{n>=0} x^n * (1 + n^2*x)^n / (1 + x + n^2*x^2)^n.
A210443
G.f.: Sum_{n>=0} x^n * (1 + n^2*x)^n / (1 + x + n^2*x^2)^n.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =6a(4) =21a(5) =150a(6) =962a(7) =8640a(8) =80220a(9) =884520a(10) =10709520a(11) =140873040a(12) =2098741680a(13) =32163828480a(14) =568234774800
External references
- oeis: A210443