a(n) = Sum_{i=0..n} C(n+1,i)*C(n-1,i-1)*C(2n-i,n).
A103882
a(n) = Sum_{i=0..n} C(n+1,i)*C(n-1,i-1)*C(2n-i,n).
Terms
- a(0) =1a(1) =2a(2) =12a(3) =92a(4) =780a(5) =7002a(6) =65226a(7) =623576a(8) =6077196a(9) =60110030a(10) =601585512a(11) =6078578508a(12) =61908797418a(13) =634756203018
External references
- oeis: A103882