A107376 a(n) = 7*a(n-1)-7*a(n-3)-a(n-4).

0, 1, 1, 2, 7, 41, 272, 1853, 12677, 86794, 594315, 4069613, 27867056, 190822393, 1306675145, 8947587010, 61269485263, 419548848433, 2872902154816, 19672481099861, 134709256274733, 922434929990986, 6316464240083059

Offset

0,4

Links

Table of n, a(n) for n=0..22.

Index entries for linear recurrences with constant coefficients, signature (7,0,-7,-1).

Formula

G.f.: x*(1-6*x-5*x^2)/(1-7*x+7*x^3+x^4). [Sep 28 2009]

Mathematica

m = 7 M = {{0, 1, 0, 0}, {0, 0, 1, 0}, {0, 0, 0, 1}, {-1, -m, 0, m}} Expand[Det[M - x*IdentityMatrix[4]]] NSolve[Det[M - x*IdentityMatrix[4]] == 0, x] v[1] = {0, 1, 1, 2}; v[n_] := v[n] = M.v[n - 1]; digits = 50; a = Table[v[n][[1]], {n, 1, digits}]
LinearRecurrence[{7, 0, -7, -1}, {0, 1, 1, 2}, 30] (* Harvey P. Dale, Oct 02 2021 *)

Crossrefs

Sequence in context: A358745 A215207 A106871 * A220896 A087804 A378325

Adjacent sequences: A107373 A107374 A107375 * A107377 A107378 A107379

Keyword

nonn,easy

Author

Roger L. Bagula, May 24 2005

Extensions

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

Status

approved