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A192309
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0-sequence of reduction of (3n-1) by x^2 -> x+1.
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3
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2, 2, 10, 21, 49, 100, 200, 384, 722, 1331, 2419, 4344, 7726, 13630, 23882, 41601, 72101, 124412, 213844, 366300, 625522, 1065247, 1809575, 3067056, 5187674, 8758010, 14760010, 24835629, 41727577, 70012756
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OFFSET
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1,1
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COMMENTS
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See A192232 for definition of "k-sequence of reduction of [sequence] by [substitution]".
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LINKS
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FORMULA
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Empirical G.f.: x*(2-4*x+6*x^2-x^3)/(1-3*x+x^2+3*x^3-x^4-x^5). [Colin Barker, Feb 09 2012]
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MATHEMATICA
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c[n_] := 3 n - 1;
Table[c[n], {n, 1, 15}]
q[x_] := x + 1;
p[0, x_] := 2; p[n_, x_] := p[n - 1, x] + (x^n)*c[n + 1]
reductionRules = {x^y_?EvenQ -> q[x]^(y/2),
x^y_?OddQ -> x q[x]^((y - 1)/2)};
t = Table[
Last[Most[
FixedPointList[Expand[#1 /. reductionRules] &, p[n, x]]]], {n, 0,
30}]
Table[Coefficient[Part[t, n], x, 0], {n, 1, 30}] (* A192309 *)
Table[Coefficient[Part[t, n], x, 1], {n, 1, 30}] (* A192310 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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