This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A173908 #23 Sep 08 2022 08:45:50
%S A173908 1,-1,1,0,0,0,1,-1,2,-2,3,-2,3,-2,4,-3,6,-5,9,-7,12,-9,16,-12,22,-17,
%T A173908 31,-24,43,-33,59,-45,81,-63,113,-88,156,-121,215,-168,298,-233,412,
%U A173908 -323,570,-448,788,-621,1090,-861,1507,-1193,2084,-1654,2882,-2293
%N A173908 Expansion of 1/(1 + x - x^3 - x^4 - x^8 - x^12 - x^13 - x^17 - x^21 - x^22 - x^26 - x^30 - x^31 + x^33 + x^34).
%C A173908 This polynomial is what I call a bi-Salem polynomial because it has two roots bigger than 1 (one positive and one negative).
%H A173908 G. C. Greubel, <a href="/A173908/b173908.txt">Table of n, a(n) for n = 0..1000</a>
%H A173908 <a href="/index/Rec#order_34">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,1,1,0,0,0,1,0,0,0,1,1,0,0,0,1,0,0,0,1,1,0,0,0,1,0,0,0,1,1,0,-1,-1).
%F A173908 a(n) = a(n-1) + (n-3) + a(n-4) + a(n-8) + a(n-12) + a(n-13) + a(n-17) + a(n-21) + a(n-22) + a(n-26) + a(n-30) + a(n-31) - a(n-33) - a(n-34). - _Franck Maminirina Ramaharo_, Nov 02 2018
%p A173908 seq(coeff(series(1/(1+x-x^3-x^4-x^8-x^12-x^13-x^17-x^21-x^22-x^26-x^30-x^31+ x^33+x^34), x, n+1), x, n), n = 0..60); # _G. C. Greubel_, Dec 15 2019
%t A173908 CoefficientList[Series[1/(1+x-x^3-x^4-x^8-x^12-x^13-x^17-x^21-x^22-x^26-x^30 - x^31+x^33+x^34), {x, 0, 60}], x]
%o A173908 (PARI) x='x+O('x^60); Vec(1/(1+x-x^3-x^4-x^8-x^12-x^13-x^17-x^21-x^22-x^26 - x^30-x^31+x^33+x^34)) \\ _G. C. Greubel_, Nov 03 2018
%o A173908 (Magma) m:=60; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/(1+x-x^3 -x^4-x^8-x^12-x^13-x^17-x^21-x^22-x^26-x^30-x^31+x^33+x^34))); // _G. C. Greubel_, Nov 03 2018
%o A173908 (Sage)
%o A173908 def A173908_list(prec):
%o A173908 P.<x> = PowerSeriesRing(ZZ, prec)
%o A173908 return P( 1/(1+x-x^3-x^4-x^8-x^12-x^13-x^17-x^21-x^22-x^26-x^30 - x^31+x^33+x^34) ).list()
%o A173908 A173908_list(30) # _G. C. Greubel_, Dec 15 2019
%Y A173908 Cf. A029826, A117791, A143419, A143438, A143472, A143619, A143644, A147663, A173908, A173911, A173924, A173925, A174522, A175740, A175772, A175773, A175782, A181600, A204631, A225391, A225393, A225394, A225482, A225499.
%K A173908 sign,easy
%O A173908 0,9
%A A173908 _Roger L. Bagula_, Nov 26 2010