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%I #14 Jul 31 2015 20:42:11
%S 1,1,4,11,29,80,219,597,1632,4459,12181,33280,90923,248405,678656,
%T 1854123,5065557,13839360,37809835,103298389,282216448,771029675,
%U 2106492245,5755043840,15723072171,42956232021,117358608384
%N Expansion of 1/(1-x-3x^2-4x^3-2x^4).
%C Diagonal sums of number triangle A124860.
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (1, 3, 4, 2).
%F a(n)=a(n-1)+3a(n-2)+4a(n-3)+2a(n-4); a(n)=sum{k=0..floor(n/2), J(n-k+1)C(n-k,k)} where J(n)=A001045(n). - corrected by Harvey P. Dale, Apr 22 2011
%F G.f.: 1 + x/(G(0) - x) where G(k) = 1 - 8*x - 2*k*x + k + 2*x*(k+1)*(k+5)/G(k+1); (continued fraction). - _Sergei N. Gladkovskii_, Apr 09 2013
%t LinearRecurrence[{1,3,4,2},{1,1,4,11},30] (* or *) CoefficientList[ Series[ 1/(1-x-3x^2-4x^3-2x^4),{x,0,30}],x] (* _Harvey P. Dale_, Apr 22 2011 *)
%K easy,nonn
%O 0,3
%A _Paul Barry_, Nov 10 2006
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