A022371 - OEIS

%I #23 Jun 26 2021 16:44:51

%S 2,18,20,38,58,96,154,250,404,654,1058,1712,2770,4482,7252,11734,

%T 18986,30720,49706,80426,130132,210558,340690,551248,891938,1443186,

%U 2335124,3778310,6113434,9891744,16005178

%N Fibonacci sequence beginning 2, 18.

%H G. C. Greubel, <a href="/A022371/b022371.txt">Table of n, a(n) for n = 0..1000</a>

%H Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (1, 1).

%F G.f.: (2+16*x)/(1-x-x^2). - _Philippe Deléham_, Nov 19 2008

%F a(n) = 2*(Fibonacci(n+2) + 7*Fibonacci(n)). - _G. C. Greubel_, Aug 27 2017

%F a(n) = 2 * A022099(n). - _Alois P. Heinz_, Aug 27 2017

%t a={};b=2;c=18;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 *)

%t Transpose[NestList[{Last[#],Total[#]}&,{2,18},30]][[1]]  (* _Harvey P. Dale_, Apr 13 2011 *)

%t LinearRecurrence[{1,1},{2,18},40] (* _Harvey P. Dale_, Jun 26 2021 *)

%o (PARI) for(n=0,50, print1(2*(fibonacci(n+2) + 7*fibonacci(n)), ", ")) \\ _G. C. Greubel_, Aug 27 2017

%Y Cf. A022099.

%K nonn

%O 0,1

%A _N. J. A. Sloane_