

A245775


Numbers k such that A017666(k) = denominator(sigma(k)/k) = 3.


8



3, 12, 84, 234, 270, 1080, 1488, 1638, 6048, 6552, 24384, 35640, 199584, 435708, 2142720, 4713984, 12999168, 18506880, 36197280, 100651008, 208565280, 240589440, 275890944, 299980800, 470564640, 3899750400, 4138364160, 6039429120, 13286744064, 17827568640
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OFFSET

1,1


COMMENTS

Numbers n such that sigma(n)/n = k + 1/3 with integer k are terms of this sequence (3, 12, 234, 1080, 6048, 6552, 435708, 4713984, ...).
Subsequence of A245774 (numbers n such that n divides 3*sigma(n)).


LINKS



EXAMPLE

Number 12 is in sequence because A017666(12) = 3.


PROG

(Magma) [n: n in [1..3000000]  Denominator((SumOfDivisors(n))/n) eq 3]
(PARI) for(n=1, 10^7, if(denominator(sigma(n)/n)==3, print1(n, ", "))) \\ Derek Orr, Aug 26 2014


CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS



STATUS

approved



