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%I #24 Jun 30 2024 10:59:26
%S 1,1,2,6,23,97,418,1800,7717,32969,140558,598590,2547851,10842145,
%T 46133086,196287336,835152025,3553338593,15118441034,64324630854,
%U 273682864751,1164442223761,4954368527338,21079421416440,89686912218205,381592176237641,1623565645450934,6907807794533022
%N Expansion of g.f. (1 - x)*(1 - 2*x)(1 - 4*x)/(1 - 8*x + 20*x^2 - 18*x^3 + 3*x^4).
%H Lapo Cioni, Luca Ferrari, and Rebecca Smith, <a href="https://arxiv.org/abs/2406.16399">Pop Stacks with a Bypass</a>, arXiv:2406.16399 [cs.DM], 2024. See p. 78.
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (8,-20,18,-3).
%F a(n) = 8*a(n-1) - 20*(n-2) + 18*a(n-3) - 3*a(n-4) for n > 3.
%t CoefficientList[Series[(1-x)(1-2x)(1-4x)/(1-8x+20x^2-18x^3+3x^4),{x,0,27}],x]
%Y Cf. A374162.
%K nonn,easy
%O 0,3
%A _Stefano Spezia_, Jun 30 2024