A027088 a(n) = A027082(n, 2n-1).

1, 3, 6, 16, 41, 107, 283, 757, 2043, 5557, 15216, 41906, 115999, 322537, 900406, 2522616, 7090307, 19987069, 56492426, 160062636, 454529595, 1293394325, 3687475479, 10531663241, 30128741717, 86324342567, 247691217352

Offset

1,2

Links

Table of n, a(n) for n=1..27.

Formula

Conjecture: D-finite with recurrence 3*(n+1)*(18*n-85)*a(n) +(292*n^2-1316*n-255)*a(n-1) +(-218*n^2+1213*n-1056)*a(n-2) +2*(-248*n^2+1666*n-2223)*a(n-3) +(-50*n^2-497*n+3243)*a(n-4) +(-52*n^2+80*n+765)*a(n-5) +3*(22*n-83)*(n-6)*a(n-6)=0. - R. J. Mathar, Jun 24 2020

Crossrefs

Cf. A027082.

Sequence in context: A128720 A096745 A293949 * A027102 A218207 A019497

Adjacent sequences: A027085 A027086 A027087 * A027089 A027090 A027091

Keyword

nonn

Author

Clark Kimberling

Status

approved