a(n) = Sum_{k=0..2*n} binomial(2*n, k)*binomial(3*n, 2*n + 2*k).
A115750
a(n) = Sum_{k=0..2*n} binomial(2*n, k)*binomial(3*n, 2*n + 2*k).
Terms
- a(0) =1a(1) =3a(2) =19a(3) =138a(4) =1051a(5) =8228a(6) =65602a(7) =529840a(8) =4320507a(9) =35492475a(10) =293285544a(11) =2435133110a(12) =20299183738a(13) =169780446228
External references
- oeis: A115750