A145626 Denominator of the polynomial A_l(x) = sum_{d=1..l-1} x^(l-d)/d for index l=2n+1 evaluated at x=9.

2, 4, 20, 280, 280, 3080, 40040, 16016, 272272, 25865840, 25865840, 594914320, 2974571600, 2974571600, 86262576400, 5348279736800, 5348279736800, 5348279736800, 10415071066400, 10415071066400, 427017913722400

Offset

1,1

Comments

For numerators see A145625. For general properties of A_l(x) see A145609.

Links

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

Mathematica

m = 9; 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: A059831 A064493 A145614 * A228808 A059588 A132498

Adjacent sequences: A145623 A145624 A145625 * A145627 A145628 A145629

Keyword

frac,nonn

Author

Artur Jasinski, Oct 14 2008

Extensions

Edited by R. J. Mathar, Aug 21 2009

Status

approved