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Expansion of 1/(1-3x*c(4x)), where c(x) is the g.f. of A000108.
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%I #19 Jan 26 2020 21:03:23

%S 1,3,21,195,2085,24243,297909,3806883,50082885,673851795,9229863381,

%T 128273819523,1804331883621,25639360102515,367507859864565,

%U 5307403512554595,77150495031376005,1127965980470739795,16575672566809158165,244695925293076974915

%N Expansion of 1/(1-3x*c(4x)), where c(x) is the g.f. of A000108.

%H Harvey P. Dale, <a href="/A132863/b132863.txt">Table of n, a(n) for n = 0..830</a>

%F a(n) = Sum_{k=0..n} A039599(n,k)*(-1)^k*4^(n-k). - _Philippe Deléham_, Dec 11 2007

%F From _Gary W. Adamson_, Jul 13 2011: (Start)

%F a(n) = upper left term in M^n, M = an infinite square production matrix as follows:

%F 3, 3, 0, 0, 0, 0, ...

%F 4, 4, 4, 0, 0, 0, ...

%F 4, 4, 4, 4, 0, 0, ...

%F 4, 4, 4, 4, 4, 0, ...

%F 4, 4, 4, 4, 4, 4, ...

%F ... (End)

%F G.f.: 8/(5 + 3*sqrt(1-16x)). - _Philippe Deléham_, Oct 27 2011

%t CoefficientList[Series[8/(5+3Sqrt[1-16x]),{x,0,30}],x] (* _Harvey P. Dale_, Mar 09 2013 *)

%K nonn

%O 0,2

%A _Philippe Deléham_, Nov 18 2007

%E More terms from _Philippe Deléham_, Oct 27 2011

%E Corrected by _Harvey P. Dale_, Mar 09 2013