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 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 (list; graph; refs; listen; history; text; internal format)
 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)). Union of A160320 (sigma(n)/n = k + 1/3) and A160321 (sigma(n)/n = k + 2/3). - Michel Marcus, Aug 27 2014 LINKS Jud McCranie, Table of n, a(n) for n = 1..44 (terms <= 10^13). 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 Cf. A000203, A007691, A160320, A160321, A245774. Sequence in context: A212718 A357846 A051549 * A277782 A066780 A328778 Adjacent sequences: A245772 A245773 A245774 * A245776 A245777 A245778 KEYWORD nonn AUTHOR Jaroslav Krizek, Aug 26 2014 EXTENSIONS More terms from A160320 and A160321 by Michel Marcus, Aug 27 2014 STATUS approved

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Last modified December 5 03:48 EST 2023. Contains 367567 sequences. (Running on oeis4.)