A234715 Denominator of sum_{k=1..n} 1/(k*H(k)) where H(k) is the harmonic number H(k) = sum_{j=1..n} 1/j.

1, 1, 3, 33, 825, 113025, 5538225, 60920475, 46360481475, 330503872435275, 20160736218551775, 1687675389591187637025, 145175524688023551724527525, 166370135063802174111446471957325, 194941377468714112878127508925972294225, 8038017817167489016303831575544615607779425

Offset

0,3

Comments

The corresponding numerators are in A234714.

A124432(n) = a(n) for 0 <= n <= 53, but A124432(54) = 3 * a(54).

Links

Table of n, a(n) for n=0..15.

Mathematica

nmax = 54; Table[ Denominator[ Sum[ 1/(k HarmonicNumber[k]), {k, 1, n} ] ], {n, 0, nmax} ]

Crossrefs

Cf. A001008, A002805, A000254, A096987, A124432, A234714

Sequence in context: A289695 A371683 A124432 * A126466 A002112 A055549

Adjacent sequences: A234712 A234713 A234714 * A234716 A234717 A234718

Keyword

nonn,easy

Author

Stuart Clary, Dec 29 2013

Status

approved