A171146 The sequence of coefficients of a polynomial recursion: p(x,n)=If[Mod[n, 2] == 0, (x + 1)*p(x, n - 1), (x^2 + (2*n - 1)*x + 1)^Floor[n/2]] ( correction).
1, 1, 1, 1, 5, 1, 1, 6, 6, 1, 1, 18, 83, 18, 1, 1, 19, 101, 101, 19, 1, 1, 39, 510, 2275, 510, 39, 1, 1, 40, 549, 2785, 2785, 549, 40, 1, 1, 68, 1738, 19856, 86995, 19856, 1738, 68, 1, 1, 69, 1806, 21594, 106851, 106851, 21594, 1806, 69, 1, 1, 105, 4415, 93030, 985645
Offset: 1
Examples
{1}, {1, 1}, {1, 5, 1}, {1, 6, 6, 1}, {1, 18, 83, 18, 1}, {1, 19, 101, 101, 19, 1}, {1, 39, 510, 2275, 510, 39, 1}, {1, 40, 549, 2785, 2785, 549, 40, 1}, {1, 68, 1738, 19856, 86995, 19856, 1738, 68, 1}, {1, 69, 1806, 21594, 106851, 106851, 21594, 1806, 69, 1}, {1, 105, 4415, 93030, 985645, 4269951, 985645, 93030, 4415, 105, 1}, {1, 106, 4520, 97445, 1078675, 5255596, 5255596, 1078675, 97445, 4520, 106, 1}
Programs
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Mathematica
Clear[p, n, x, a] p[x, 1] := 1; p[x_, n_] := p[x, n] = If[Mod[n, 2] == 0, (x + 1)*p[x, n - 1], (x^2 + (2*n - 1)*x + 1)^Floor[n/2]]; a = Table[CoefficientList[p[x, n], x], {n, 1, 12}]; Flatten[a]
Formula
p(x,n)=If[Mod[n, 2] == 0, (x + 1)*p(x, n - 1), (x^2 + (2*n - 1)*x + 1)^Floor[n/2]]
Comments