A027202 a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A026714.

1, 6, 35, 196, 1041, 5778, 29928, 165372, 847768, 4670704, 23822408, 130996724, 666301327, 3659417070, 18584154238, 101986105620, 517452054522, 2838222123890, 14392322734127, 78915504085490, 400031746789975, 2192959234558576

Offset

1,2

Links

Table of n, a(n) for n=1..22.

Maple

A027202 := proc(n)
    add( A026714(n, k)*A026714(n, k+1), k=0..n-1) ;
end proc:
seq(A027202(n), n=1..30) ; # R. J. Mathar, Oct 21 2019

Crossrefs

Sequence in context: A328331 A346318 A009572 * A026934 A171311 A230713

Adjacent sequences: A027199 A027200 A027201 * A027203 A027204 A027205

Keyword

nonn

Author

Clark Kimberling

Extensions

Name corrected by Sean A. Irvine, Oct 21 2019

More terms from Ray Chandler, Oct 22 2019

Status

approved