a(n) = (1/2) * Sum_{k=0..n} (binomial(n,k) * binomial(n+k,k+1))^2 for n >= 0.
A277060
a(n) = (1/2) * Sum_{k=0..n} (binomial(n,k) * binomial(n+k,k+1))^2 for n >= 0.
Terms
- a(0) =0a(1) =1a(2) =28a(3) =729a(4) =19376a(5) =529575a(6) =14835780a(7) =424231465a(8) =12338211520a(9) =363931754949
External references
- oeis: A277060