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Search: id:A145613
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| A145613 |
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Numerator of the polynomial A_l(x) = sum_{d=1..l-1} x^(l-d)/d for index l=2n+1 evaluated at x=3. |
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+0
2
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| 21, 393, 17731, 2234571, 20111503, 1991042087, 33278851497, 119803867191, 54989975121893, 15672142912044093, 987345003473390379, 204380415719298965303, 9197118707369867504211, 248322205098990353297597
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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For denominators see A145614. For general properties of A_l(x) see A145609.
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MAPLE
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A := proc(l, x) add(x^(l-d)/d, d=1..l-1) ; end: A145613 := proc(n) numer( A(2*n+1, 3)) ; end: seq(A145613(n), n=1..20) ; # R. J. Mathar, Aug 21 2009
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MATHEMATICA
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m = 3; aa = {}; Do[k = 0; Do[k = k + m^(2 r + 1 - d)/d, {d, 1, 2 r}]; AppendTo[aa, Numerator[k]], {r, 1, 25}]; aa (*Artur Jasinski*)
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CROSSREFS
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Cf. A145609 - A145640.
Sequence in context: A001881 A108740 A094172 this_sequence A015677 A113363 A014903
Adjacent sequences: A145610 A145611 A145612 this_sequence A145614 A145615 A145616
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KEYWORD
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frac,nonn
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AUTHOR
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Artur Jasinski (grafix(AT)csl.pl), Oct 14 2008
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EXTENSIONS
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Edited by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 21 2009
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