A026915 a(n) = T(n,0) + T(n,1) + ... + T(n,n), T given by A026907.

1, 26, 100, 272, 640, 1400, 2944, 6056, 12304, 24824, 49888, 100040, 200368, 401048, 802432, 1605224, 3210832, 6422072, 12844576, 25689608, 51379696, 102759896, 205520320, 411041192, 822082960, 1644166520, 3288333664, 6576667976, 13153336624, 26306673944

Offset: 0

Author

Clark Kimberling

Keywords

• nonn
• easy

Links

• Colin Barker, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (4,-5,2).

Programs

PARI

Vec((1+22*x+x^2)/((1-x)^2*(1-2*x)) + O(x^40)) \\ Colin Barker, Feb 18 2016

Formula

a(n) = 49*2^n - 24*n - 48.

a(n) = 4*a(n-1)-5*a(n-2)+2*a(n-3) for n>2. G.f.: (1+22*x+x^2) / ((1-x)^2*(1-2*x)). - Colin Barker, Feb 18 2016