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A249139
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Triangular array read by rows: row n gives the coefficients of the polynomial p(n,x) defined in Comments.
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1
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1, 3, 1, 5, 2, 11, 7, 1, 21, 16, 3, 43, 41, 12, 1, 85, 94, 34, 4, 171, 219, 99, 18, 1, 341, 492, 261, 60, 5, 683, 1101, 678, 195, 25, 1, 1365, 2426, 1692, 576, 95, 6, 2731, 5311, 4149, 1644, 340, 33, 1, 5461, 11528, 9959, 4488, 1106, 140, 7, 10923, 24881
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OFFSET
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0,2
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COMMENTS
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The polynomial p(n,x) is the numerator of the rational function given by f(n,x) = 1 + (x + 2)/f(n-1,x), where f(0,x) = 1.
(Sum of numbers in row n) = A006130(n+1) for n >= 0.
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LINKS
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EXAMPLE
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f(0,x) = 1/1, so that p(0,x) = 1
f(1,x) = (3 + x)/1, so that p(1,x) = 3 + x;
f(2,x) = (5 + 2 x)/(3 + x), so that p(2,x) = 5 + 2 x.
First 6 rows of the triangle of coefficients:
1
3 1
5 2
11 7 1
21 16 3
43 41 12 1
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MATHEMATICA
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z = 15; f[x_, n_] := 1 + (x + 2)/f[x, n - 1]; f[x_, 1] = 1;
t = Table[Factor[f[x, n]], {n, 1, z}]
u = Numerator[t]
TableForm[Table[CoefficientList[u[[n]], x], {n, 1, z}]] (* A249139 array *)
Flatten[CoefficientList[u, x]] (* A249139 sequence *)
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CROSSREFS
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KEYWORD
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nonn,tabf,easy
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AUTHOR
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STATUS
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approved
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