Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #17 Jun 21 2016 02:41:48
%S 1,5,13,35,79,185,397,875,1831,3905,8053,16835,34399,70985,144157,
%T 294875,596311,1212305,2444293,4947635,9954319,20085785,40348717,
%U 81228875,162989191,327572705,656739733,1318262435,2641307839,5296964585,10608278077,21259602875
%N a(n) = 10*2^n - 3*A083658(n+2).
%C The sequence can be defined as the row sums of the triangle T(n,k)
%C .1;
%C .3,.2;
%C .3,.6,.4;
%C .9,.6,12,.8;
%C .9,18,12,24,16;
%C 27,18,36,24,48,32;
%C with left column A162436, diagonal the powers of 2, and the recurrence T(n+2,k) = 3*T(n,k).
%H G. C. Greubel, <a href="/A167710/b167710.txt">Table of n, a(n) for n = 0..1000</a>
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (2,3,-6).
%F a(n+1) - 2*a(n) = A162436(n+2).
%F a(n) = 2*a(n-1) + 3*a(n-2) - 6*a(n-3).
%F G.f.: (1+3*x)/((2*x-1) * (3*x^2-1)). - _R. J. Mathar_, Feb 27 2010
%t LinearRecurrence[{2,3,-6},{1,5,13},40] (* _Harvey P. Dale_, Oct 03 2014 *)
%K nonn,easy
%O 0,2
%A _Paul Curtz_, Nov 10 2009
%E Replaced cross-references by link to the index - _R. J. Mathar_, Feb 27 2010