a(n) = Sum_{k = 0..n} C(n,k) * C(n+k,k) * C(n+2*k,k).
A081798
a(n) = Sum_{k = 0..n} C(n,k) * C(n+k,k) * C(n+2*k,k).
Terms
- a(0) =1a(1) =7a(2) =115a(3) =2371a(4) =54091a(5) =1307377a(6) =32803219a(7) =844910395a(8) =22188235867a(9) =591446519797
External references
- oeis: A081798