A145614 Denominator 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, 4, 20, 280, 280, 3080, 5720, 2288, 116688, 3695120, 25865840, 594914320, 2974571600, 8923714800, 86262576400, 5348279736800, 5348279736800, 16044839210400, 197886350261600, 15222026943200, 89157586381600

Offset

1,1

Comments

For numerators see A145613. For general properties of A_l(x) see A145609.

Links

Table of n, a(n) for n=1..21.

Mathematica

m = 3; aa = {}; Do[k = 0; Do[k = k + m^(2 r + 1 - d)/d, {d, 1, 2 r}]; AppendTo[aa, Denominator[k]], {r, 1, 30}]; aa (*Artur Jasinski*)

Crossrefs

Cf. A145609 - A145640.

Sequence in context: A127103 A059831 A064493 * A145626 A228808 A059588

Adjacent sequences: A145611 A145612 A145613 * A145615 A145616 A145617

Keyword

frac,nonn

Author

Artur Jasinski, Oct 14 2008

Extensions

Edited by R. J. Mathar, Aug 21 2009

Status

approved