a(n) = (sum_{k=0}^{n-1} (2k+1)*C(n-1,k)^2*C(n+k,k)^2)/n^2, where C(n,k) denotes the binomial coefficient n!/(k!(n-k)!).
A246460
a(n) = (sum_{k=0}^{n-1} (2k+1)*C(n-1,k)^2*C(n+k,k)^2)/n^2, where C(n,k) denotes the binomial coefficient n!/(k!(n-k)!).
Terms
- a(0) =1a(1) =7a(2) =77a(3) =1211a(4) =23009a(5) =489035a(6) =11203765a(7) =270937315a(8) =6825612185a(9) =177559028087
External references
- oeis: A246460