a(n) = Sum_{k=1..n} ((-1)^(n-k) * k / ((n+1)^2 + (k-1)*(n+1))) * binomial(n+1, k+1) * binomial(n+k, k)^2.
A271777
a(n) = Sum_{k=1..n} ((-1)^(n-k) * k / ((n+1)^2 + (k-1)*(n+1))) * binomial(n+1, k+1) * binomial(n+k, k)^2.
Terms
- a(0) =0a(1) =1a(2) =3a(3) =16a(4) =105a(5) =771a(6) =6083a(7) =50464a(8) =434493a(9) =3849715a(10) =34895685a(11) =322239204a(12) =3021922137a(13) =28710585099a(14) =275827551795
External references
- oeis: A271777