a(n) = Sum_{k=0..2n-1} T(n,k) * T(n,k+1), with T given by A025177.
A027258
a(n) = Sum_{k=0..2n-1} T(n,k) * T(n,k+1), with T given by A025177.
Terms
- a(0) =0a(1) =6a(2) =52a(3) =428a(4) =3552a(5) =29790a(6) =251980a(7) =2145822a(8) =18373296a(9) =158025186a(10) =1364247180a(11) =11815188000a(12) =102606325136a(13) =893175905778
External references
- oeis: A027258