A022131 Fibonacci sequence beginning 4, 11.

4, 11, 15, 26, 41, 67, 108, 175, 283, 458, 741, 1199, 1940, 3139, 5079, 8218, 13297, 21515, 34812, 56327, 91139, 147466, 238605, 386071, 624676, 1010747, 1635423, 2646170, 4281593, 6927763, 11209356, 18137119, 29346475, 47483594, 76830069, 124313663

Offset

0,1

Links

Table of n, a(n) for n=0..35.

Tanya Khovanova, Recursive Sequences

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

Formula

G.f.: (4+7x)/(1-x-x^2). - Philippe Deléham, Nov 19 2008

a(n) = ((10 + 9*sqrt(5))/5)*((1 + sqrt(5))/2)^n + ((10 - 9*sqrt(5))/5)*((1 - sqrt(5))/2)^n starting at n=0. - Bogart B. Strauss, Oct 27 2013

Mathematica

a={}; b=4; c=11; 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 17 2008 *)
LinearRecurrence[{1, 1}, {4, 11}, 40] (* Harvey P. Dale, May 08 2018 *)

Crossrefs

Cf. A000032.

Sequence in context: A003250 A320494 A190509 * A091391 A135105 A330338

Adjacent sequences: A022128 A022129 A022130 * A022132 A022133 A022134

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved