A026658 Sum{T(n-k,k)}, 0<=k<=[ n/2 ], T given by A026648.

1, 1, 2, 4, 6, 11, 17, 30, 47, 86, 133, 242, 375, 679, 1054, 1914, 2968, 5389, 8357, 15166, 23523, 42698, 66221, 120204, 186425, 338381, 524806, 952592, 1477398, 2681683, 4159081, 7549278, 11708359, 21252226, 32960585, 59827870

Offset: 0

Author

Clark Kimberling

Keywords

• nonn

Formula

G.f.: (-x^6+2x^5+x^4+2x^3+x+1)/(x^8-4x^6-x^4-2x^2+1).