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A099008 Numbers n such that the denominator of the 2n-th Bernoulli number is divisible by n but sum_{d|n} sigma(d)/phi(d) is not an integer. 0
546, 903, 1806, 2730, 6162, 6510, 9030, 10230, 12090, 12246, 12810, 15834, 20130, 20670, 23478, 23790, 28938, 30030, 30810, 43134, 44310, 52374, 56730, 61230, 71610, 79170, 84630, 85722, 88410, 99330, 109230, 117390, 132990, 140910, 144690, 154770, 164010 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Intersection of A106741 and complement of A068991. - Michel Marcus, Dec 07 2013

LINKS

Table of n, a(n) for n=1..37.

EXAMPLE

The denominator of the 1806th Bernoulli number is 1806 and Sum_{d|1806} sigma(d)/phi(d) = 172/3 is not an integer.

PROG

(PARI) lista() = {v = readvec("b106741.txt"); for (i=1, #v, vi = v[i]; if (denominator(sumdiv(vi, d, sigma(d)/eulerphi(d))) != 1, print1(vi, ", "))); } \\ Michel Marcus, Dec 07 2013

CROSSREFS

Cf. A068991.

Sequence in context: A184379 A053327 A252537 * A248442 A043479 A002606

Adjacent sequences:  A099005 A099006 A099007 * A099009 A099010 A099011

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Nov 07 2004

EXTENSIONS

Extended using b-file from A106741 by Michel Marcus, Dec 07 2013

STATUS

approved

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Last modified May 21 15:06 EDT 2019. Contains 323443 sequences. (Running on oeis4.)