cp's OEIS Frontend

A174317 a(0)=1, a(1)=2, a(2)=1; for n>2, a(n) = 7*2^(n-3)-2.

%I A174317 #10 Mar 01 2016 17:13:48
%S A174317 1,2,1,5,12,26,54,110,222,446,894,1790,3582,7166,14334,28670,57342,
%T A174317 114686,229374,458750,917502,1835006,3670014,7340030,14680062,
%U A174317 29360126,58720254,117440510,234881022,469762046,939524094,1879048190,3758096382
%N A174317 a(0)=1, a(1)=2, a(2)=1; for n>2, a(n) = 7*2^(n-3)-2.
%H A174317 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (3,-2).
%F A174317 G.f: (1+x-x^2+4*x^3-7*x^4)/(1-x)+(14*x^4)/(1-2*x).
%F A174317 a(n) = A026622(n-1), n>2. a(n) = A176448(n-3), n>2. - _R. J. Mathar_, Mar 01 2016
%e A174317 a(4) = 14-2 = 12.
%e A174317 a(5) = 7*4-2 = 26.
%p A174317 taylor(1+2*z+z^2+5*z^3-((2*z^4)/(1-z))+((14*z^4)/(1-2*z)),z=0,50);
%Y A174317 Cf. A174314, A174316
%K A174317 nonn,easy
%O A174317 0,2
%A A174317 _Richard Choulet_, Mar 15 2010
%E A174317 Definition edited by _Olivier Gérard_, Oct 24 2012