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 A171146 #5 Jun 02 2025 02:13:17
%S A171146 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,
%T A171146 39,1,1,40,549,2785,2785,549,40,1,1,68,1738,19856,86995,19856,1738,68,
%U A171146 1,1,69,1806,21594,106851,106851,21594,1806,69,1,1,105,4415,93030,985645
%N 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).
%C A171146 Row sums are:
%C A171146 {1, 2, 7, 14, 121, 242, 3375, 6750, 130321, 260642, 6436343, 12872686...}.
%F A171146 p(x,n)=If[Mod[n, 2] == 0, (x + 1)*p(x, n - 1), (x^2 + (2*n - 1)*x + 1)^Floor[n/2]]
%e A171146 {1},
%e A171146 {1, 1},
%e A171146 {1, 5, 1},
%e A171146 {1, 6, 6, 1},
%e A171146 {1, 18, 83, 18, 1},
%e A171146 {1, 19, 101, 101, 19, 1},
%e A171146 {1, 39, 510, 2275, 510, 39, 1},
%e A171146 {1, 40, 549, 2785, 2785, 549, 40, 1},
%e A171146 {1, 68, 1738, 19856, 86995, 19856, 1738, 68, 1},
%e A171146 {1, 69, 1806, 21594, 106851, 106851, 21594, 1806, 69, 1},
%e A171146 {1, 105, 4415, 93030, 985645, 4269951, 985645, 93030, 4415, 105, 1},
%e A171146 {1, 106, 4520, 97445, 1078675, 5255596, 5255596, 1078675, 97445, 4520, 106, 1}
%t A171146 Clear[p, n, x, a]
%t A171146 p[x, 1] := 1;
%t A171146 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]];
%t A171146 a = Table[CoefficientList[p[x, n], x], {n, 1, 12}];
%t A171146 Flatten[a]
%Y A171146 Cf. A051159 , A169623, A007318, A171142, A171143
%K A171146 nonn,tabl
%O A171146 1,5
%A A171146 _Roger L. Bagula_ and _Gary W. Adamson_, Dec 04 2009