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A145613 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. 2
21, 393, 17731, 2234571, 20111503, 1991042087, 33278851497, 119803867191, 54989975121893, 15672142912044093, 987345003473390379, 204380415719298965303, 9197118707369867504211, 248322205098990353297597 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
For denominators see A145614. For general properties of A_l(x) see A145609.
LINKS
MAPLE
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
MATHEMATICA
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 *)
a[n_, m_]:=Integrate[(m-x^n)/(m-x), {x, 0, 1}]+(m^n-m)Log[m/(m-1)]
Table[3 a[2 n, 3] //FullSimplify //Numerator, {n, 1, 10}] (* Gerry Martens , Jun 04 2016 *)
CROSSREFS
Sequence in context: A372904 A094172 A296723 * A212786 A015677 A285396
KEYWORD
frac,nonn
AUTHOR
Artur Jasinski, Oct 14 2008
EXTENSIONS
Edited by R. J. Mathar, Aug 21 2009
STATUS
approved

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Last modified May 21 02:29 EDT 2024. Contains 372720 sequences. (Running on oeis4.)