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A160089
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The maximum of the absolute value of the coefficients of Pn=(1-x)(1-x^2)(1-x^3)...(1-x^n).
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2
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1, 1, 1, 2, 1, 2, 2, 2, 2, 3, 2, 4, 3, 3, 4, 6, 5, 6, 7, 8, 8, 10, 11, 16, 16, 19, 21, 28, 29, 34, 41, 50, 56, 68, 80, 100, 114, 135, 158, 196, 225, 269, 320, 388, 455, 544, 644, 786, 921, 1111, 1321, 1600, 1891, 2274, 2711, 3280, 3895, 4694, 5591, 6780, 8051, 9729, 11624
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,4
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COMMENTS
| If n is even then a(n) is the absolute value of the coefficient of z^(n(n+1)/4). If n is odd, it is an open question as to which coefficient is a(n).
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LINKS
| Theodore Kolokolnikov, Table of n, a(n) for n=1..100
S. R. Finch, Signum equations and extremal coefficients.
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FORMULA
| a(n) >= A086376(n). - R. J. Mathar, Jun 01 2011
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MAPLE
| A160089 := proc(n)
g := expand(mul( 1-x^k, k=1..n) );
convert(PolynomialTools[CoefficientVector](g, x), list):
max(op(map(abs, %)));
end proc:
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CROSSREFS
| Cf. A025591, A063866, A069918
Sequence in context: A112220 A185278 A086376 * A129363 A053597 A094570
Adjacent sequences: A160086 A160087 A160088 * A160090 A160091 A160092
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KEYWORD
| nonn
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AUTHOR
| Theodore Kolokolnikov (tkolokol(AT)gmail.com), May 01 2009
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