a(n) = Sum_{k=0..n} binomial(n+k+2,k)*binomial(2*n+1,n-k).
A275827
a(n) = Sum_{k=0..n} binomial(n+k+2,k)*binomial(2*n+1,n-k).
Terms
- a(0) =1a(1) =7a(2) =50a(3) =364a(4) =2688a(5) =20064a(6) =151008a(7) =1144000a(8) =8712704a(9) =66646528a(10) =511673344a(11) =3940579328a(12) =30429184000a(13) =235521884160
External references
- oeis: A275827