A131137 Denominator of (exponential) expansion of log((2*x/3-1)/(x-1)).
1, 3, 9, 27, 27, 81, 243, 243, 729, 2187, 729, 2187, 6561, 6561, 19683, 59049, 59049, 177147, 531441, 177147, 531441, 1594323, 1594323, 4782969, 14348907, 14348907, 43046721, 129140163, 14348907, 43046721, 129140163, 129140163, 387420489
Offset: 0
Links
- Vincenzo Librandi, Table of n, a(n) for n = 0..200
Crossrefs
Cf. A131136.
Programs
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Mathematica
Denominator[CoefficientList[Series[Log[(2 x/3 - 1)/(x - 1)], {x, 0, 32}], x] Range[0, 32]!]; (* or *) Prepend[Table[Denominator[(1 - (2/3)^n) (n - 1)!], {n, 32}], 1]; (* or *) Join[{1, 3}, Table[Denominator[PolyLog[-n, 1/4]/4 ], {n, 31}]] (* Wouter Meeussen, Feb 13 2014 *) -
PARI
a(n)=if(n<4,3^n,denominator(polylog(1-n,1/4)/4)) \\ Charles R Greathouse IV, Jul 15 2014
Comments