A026975 a(n) = Sum_{k=0..n} (k+1) * A026648(n,k).

1, 3, 10, 25, 66, 154, 392, 882, 2180, 4796, 11640, 25220, 60424, 129480, 307264, 652936, 1538064, 3247024, 7604000, 15968400, 37217312, 77818016, 180652416, 376359200, 870795328, 1808574912, 4172640640, 8643327040

Offset

0,2

Links

Table of n, a(n) for n=0..27.

Formula

Conjectures from Colin Barker, Feb 18 2016: (Start)

a(n) = 8*a(n-2)-12*a(n-4)-16*a(n-6)-4*a(n-8) for n>7.

G.f.: (1+3*x+2*x^2+x^3-2*x^4-10*x^5-2*x^7) / (1-4*x^2-2*x^4)^2.

(End)

Crossrefs

Sequence in context: A176610 A026965 A130783 * A296668 A026985 A319919

Adjacent sequences: A026972 A026973 A026974 * A026976 A026977 A026978

Keyword

nonn

Author

Clark Kimberling

Status

approved