%I #17 Aug 27 2017 17:46:00
%S 2,20,22,42,64,106,170,276,446,722,1168,1890,3058,4948,8006,12954,
%T 20960,33914,54874,88788,143662,232450,376112,608562,984674,1593236,
%U 2577910,4171146,6749056,10920202
%N Fibonacci sequence beginning 2, 20.
%H G. C. Greubel, <a href="/A022372/b022372.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+18*x)/(1-x-x^2). - _Philippe Deléham_, Nov 19 2008
%F a(n) = 2*(Fibonacci(n+2) + 8*Fibonacci(n)). - _G. C. Greubel_, Aug 27 2017
%F a(n) = 2*A022100(n). - _Alois P. Heinz_, Aug 27 2017
%t a={};b=2;c=20;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 Table[2*(Fibonacci[n + 2] + 8*Fibonacci[n]), {n,0,50}] (* or *) LinearRecurrence[{1,1}, {2,20}, 50] (* _G. C. Greubel_, Aug 27 2017 *)
%o (PARI) for(n=0,50, print1(2*(fibonacci(n+2) + 8*fibonacci(n)), ", ")) \\ _G. C. Greubel_, Aug 27 2017
%Y Cf. A022100.
%K nonn
%O 0,1
%A _N. J. A. Sloane_