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A281048 Expansion of x*(1 - x)*Product_{k>=0} (1 + x^(2^k) - x^(2^(k+1))). 1
1, 0, -1, 1, -2, 1, 1, 0, -3, 1, 2, -1, 1, 0, -1, 1, -4, 1, 3, -2, 3, -1, -2, 1, 1, 0, -1, 1, -2, 1, 1, 0, -5, 1, 4, -3, 5, -2, -3, 1, 4, -1, -3, 2, -3, 1, 2, -1, 1, 0, -1, 1, -2, 1, 1, 0, -3, 1, 2, -1, 1, 0, -1, 1, -6, 1, 5, -4, 7, -3, -4, 1, 7, -2, -5, 3, -4, 1, 3, -2, 5, -1, -4, 3, -5, 2, 3, -1, -4, 1, 3, -2, 3, -1, -2, 1, 1, 0, -1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,5
COMMENTS
First differences of A005590.
LINKS
R. Stephan, Divide-and-conquer generating functions. I. Elementary sequences, arXiv:math/0307027 [math.CO], 2003.
FORMULA
G.f.: x*(1 - x)*Product_{k>=0} (1 + x^(2^k) - x^(2^(k+1))).
MATHEMATICA
Rest[CoefficientList[Series[x (1 - x) Product[1 + x^2^k - x^2^(k + 1), {k, 0, 15}], {x, 0, 100}], x]]
Differences[a[0] = 0; a[1] = 1; a[n_] := a[n] = If[OddQ[n], a[(n-1)/2 + 1] - a[(n-1)/2], a[n/2]]; Table[a[n], {n, 0, 100}]]
CROSSREFS
Sequence in context: A129334 A116399 A116405 * A340031 A029352 A340011
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, Feb 27 2017
STATUS
approved

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Last modified April 24 06:14 EDT 2024. Contains 371918 sequences. (Running on oeis4.)