a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A026780.
A027248
a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A026780.
Terms
- a(0) =1a(1) =6a(2) =29a(3) =156a(4) =741a(5) =3958a(6) =19233a(7) =103340a(8) =513829a(9) =2782642a(10) =14111035a(11) =76987001a(12) =396866211a(13) =2179190558a(14) =11387537287a(15) =62869497136a(16) =332264796115
External references
- oeis: A027248