a(n) = Sum_{k=0..n} T(n,k) * T(n,n+k), with T given by A027113.
A027140
a(n) = Sum_{k=0..n} T(n,k) * T(n,n+k), with T given by A027113.
Terms
- a(0) =1a(1) =3a(2) =12a(3) =57a(4) =264a(5) =1261a(6) =6141a(7) =30276a(8) =150853a(9) =758145a(10) =3836896a(11) =19534086a(12) =99957904a(13) =513756551a(14) =2650822585a(15) =13724435509a(16) =71275344341a(17) =371177285715
External references
- oeis: A027140