A022368 Fibonacci sequence beginning 2, 12.

2, 12, 14, 26, 40, 66, 106, 172, 278, 450, 728, 1178, 1906, 3084, 4990, 8074, 13064, 21138, 34202, 55340, 89542, 144882, 234424, 379306, 613730, 993036, 1606766, 2599802, 4206568, 6806370, 11012938

Offset

0,1

Links

G. C. Greubel, Table of n, a(n) for n = 0..1000

Tanya Khovanova, Recursive Sequences

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

Formula

G.f.: 2*(1+5*x)/(1-x-x^2). - Philippe Deléham, Nov 19 2008

a(n) = 2*A022096(n). - R. J. Mathar, Sep 27 2014

a(n) = 2*(Fibonacci(n+2) + 4*Fibonacci(n)). - G. C. Greubel, Aug 27 2017

Mathematica

a={}; b=2; c=12; AppendTo[a, b]; AppendTo[a, c]; Do[b=b+c; AppendTo[a, b]; c=b+c; AppendTo[a, c], {n, 4!}]; a (* Vladimir Joseph Stephan Orlovsky, Sep 18 2008 *)
Table[2*(Fibonacci[n + 2] + 4*Fibonacci[n]), {n, 0, 50}] (* or *) LinearRecurrence[{1, 1}, {2, 12}, 50] (* G. C. Greubel, Aug 27 2017 *)

Prog

(PARI) for(n=0, 50, print1(2*(fibonacci(n+2) + 4*fibonacci(n)), ", ")) \\ G. C. Greubel, Aug 27 2017

Crossrefs

Sequence in context: A108976 A073598 A232768 * A076484 A259128 A280942

Adjacent sequences: A022365 A022366 A022367 * A022369 A022370 A022371

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved