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 A231148 #4 Nov 07 2013 03:33:00
%S A231148 1,-1,1,1,1,-1,-1,1,1,-1,1,2,-1,-2,1,1,1,-1,-3,2,5,-2,-3,1,1,-1,1,4,
%T A231148 -3,-8,5,8,-3,-4,1,1,1,-1,-5,4,12,-8,-15,8,12,-4,-5,1,1,-1,1,6,-5,-17,
%U A231148 12,27,-15,-27,12,17,-5,-6,1,1,1,-1,-7,6,23,-17,-44
%N A231148 Array of coefficients of numerator polynomials of the rational function p(n, x - 1/x), where p(n,x) = (x^n - 1)/(x - 1).
%e A231148 First 4 rows:
%e A231148 1
%e A231148 -1 1 1
%e A231148 1 -1 -1 1 1
%e A231148 -1 1 2 -1 -2 1 1
%e A231148 First 4 polynomials: 1, -1 + x + x^2, 1 - x - x^2 + x^3 + x^4
%t A231148 z = 60; p[n_, x_] := p[x] = (x^n - 1)/(x - 1); Table[p[n, x], {n, 1, z/4}]; f1[n_, x_] := f1[n, x] = Numerator[Factor[p[n, x] /. x -> x - 1/x]]; Table[Expand[f1[n, x]], {n, 0, z/4}]
%t A231148 Flatten[Table[CoefficientList[f1[n, x], x], {n, 1, z/4}]]
%Y A231148 Cf. A231147.
%K A231148 tabf,sign,easy
%O A231148 1,12
%A A231148 _Clark Kimberling_, Nov 05 2013