Michael De Vlieger, <a href="/A181474/b181474_1.txt">Table of n, a(n) for n = 0..10000</a>
Michael De Vlieger, <a href="/A181474/b181474_1.txt">Table of n, a(n) for n = 0..10000</a>
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<a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (1,4,-4,-6,6,4,-4,-1,1).
a(n) = 2^n*(n+2)*(n+3)*Gamma(floor(n/2)+3)*Gamma(floor((n+1)/2)+1/2)/(12n!*sqrt(piPi)) (suggested by WolframAlpha).
a(n) = +a(n-1) +4*a(n-2) -4*a(n-3) -6*a(n-4) +6*a(n-5) +4*a(n-6) -4*a(n-7) -a(n-8) +a(n-9). a(n) = (n+3)*(n+2)*(2*n^2+2*(-1)^n*n+10*n+5*(-1)^n+11)/96. [From __R. J. Mathar_, Oct 23 2010]
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Michael De Vlieger, <a href="/A181474/b181474_1.txt">Table of n, a(n) for n = 0..10000</a>
CoefficientList[Series[(1 + x + 4 x^2 + x^3 + x^4)/((1 - x)^5 (1 + x)^4), {x, 0, 36}], x] (* Michael De Vlieger, Jul 25 2023 *)
Nathaniel K. Green and Edward D. Kim, <a href="https://arxiv.org/abs/2307.06311">Further techniques on a polynomial positivity question of Collins, Dykema, and Torres-Ayala</a>, arXiv:2307.06311 [math.OC], 2023. See p. 18.
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<a href="/index/Rec">Index to sequences with entries for linear recurrences with constant coefficients</a>, signature (1,4,-4,-6,6,4,-4,-1,1).
<a href="/index/Rea#recLCCRec">Index to sequences with linear recurrences with constant coefficients</a>, signature (1,4,-4,-6,6,4,-4,-1,1).
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