A015562 Expansion of x/(1 - 7*x - 5*x^2).

0, 1, 7, 54, 413, 3161, 24192, 185149, 1417003, 10844766, 82998377, 635212469, 4861479168, 37206416521, 284752311487, 2179298263014, 16678849398533, 127648437104801, 976933306726272, 7476775332607909, 57222093861886723

Offset

0,3

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (7,5).

Formula

a(n) = 7*a(n-1) + 5*a(n-2).

Mathematica

Join[{a=0, b=1}, Table[c=7*b+5*a; a=b; b=c, {n, 100}]] (* Vladimir Joseph Stephan Orlovsky, Jan 17 2011 *)
LinearRecurrence[{7, 5}, {0, 1}, 30] (* Vincenzo Librandi, Nov 14 2012 *)

Prog

(Sage) [lucas_number1(n, 7, -5) for n in range(0, 21)] # Zerinvary Lajos, Apr 24 2009
(Magma) [n le 2 select n-1 else 7*Self(n-1) + 5*Self(n-2): n in [1..30]]; // Vincenzo Librandi, Nov 14 2012
(PARI) x='x+O('x^30); concat([0], Vec(x/(1-7*x-5*x^2))) \\ G. C. Greubel, Dec 30 2017

Crossrefs

Sequence in context: A204258 A081008 A116472 * A243670 A152108 A093742

Adjacent sequences: A015559 A015560 A015561 * A015563 A015564 A015565

Keyword

nonn,easy

Author

Olivier Gérard

Status

approved