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A104042
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Numerators of coefficients in expansion of x^-2*(1-exp(-2*x))^2.
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3
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4, -8, 28, -8, 248, -16, 508, -136, 584, -496, 16376, -16, 131056, -174752, 18724, -2056, 1048568, -1168, 4194296, -20336, 684784, -1945184, 67108856, -3856, 536870896, -715827872, 306783376, -19746976, 17179869152, -3198784, 8589934588, -134744072, 426829048, -91625968976
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| Suggested by Bill Gosper's remarkable identity (in a posting to math-fun list, Apr 14 2005): Product_{ n >= 0 } tanh(2^n x)^(1/2^n) = (1-exp(-2*x))^2.
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MATHEMATICA
| Numerator[ CoefficientList[ Series[x^-2*(1 - E^(-2x))^2, {x, 0, 33}], x]] (from Robert G. Wilson v (rgwv(AT)rgwv.com), Apr 20 2005)
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CROSSREFS
| Cf. A104097, A104007, A104042.
Sequence in context: A036720 A110132 A099513 * A117864 A020138 A090083
Adjacent sequences: A104039 A104040 A104041 * A104043 A104044 A104045
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KEYWORD
| sign,frac
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Apr 18 2005
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