G.f.: Sum_{n>=0} x^n * Product_{k=1..n} (k^2 + x) / (1 + k^2*x + x^2).
A210438
G.f.: Sum_{n>=0} x^n * Product_{k=1..n} (k^2 + x) / (1 + k^2*x + x^2).
Terms
- a(0) =1a(1) =1a(2) =4a(3) =20a(4) =174a(5) =2262a(6) =40894a(7) =980590a(8) =30095022a(9) =1149982990a(10) =53521460958
External references
- oeis: A210438