A107298 a(n) = 3*a(n-1)-a(n-2)-2*a(n-3)+a(n-4), n>5.

3, 2, 5, 10, 25, 56, 128, 288, 649, 1459, 3280, 7371, 16564, 37220, 83634, 187925, 422265, 948822, 2131985, 4790528, 10764220, 24186984, 54347661, 122118087, 274396852, 616564131

Offset

0,1

Links

Table of n, a(n) for n=0..25.

Index entries for linear recurrences with constant coefficients, signature (3, -1, -2, 1).

Formula

G.f.: (-2*x^2-3*x^3+x^5-3+7*x-x^4)/( (x-1)*(x^3-x^2-2*x+1)) . [Sep 28 2009]

Mathematica

NSolve[x^3 - 2*x^2 - x + 1 == 0, x] b1 = -0.8019377358048383 b2 = 0.5549581320873712 b3 = 2.2469796037174667 digits = 25 a = Table[2*(b3^n + b1^n + b2^n)/ (b3 + b2 + b1), {n, 0, digits}] Floor[a]
LinearRecurrence[{3, -1, -2, 1}, {3, 2, 5, 10, 25, 56}, 30] (* Harvey P. Dale, Jun 07 2015 *)

Crossrefs

Sequence in context: A100885 A209199 A215328 * A195104 A338879 A257905

Adjacent sequences: A107295 A107296 A107297 * A107299 A107300 A107301

Keyword

nonn,easy

Author

Roger L. Bagula, May 20 2005

Extensions

Definition replaced by recurrence by the Associate Editors of the OEIS, Sep 28 2009

Status

approved