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A067246 Numbers k such that phi(k) divides sigma(k+1) + sigma(k). 1
1, 2, 6, 8, 11, 14, 22, 30, 70, 86, 102, 116, 130, 140, 154, 186, 238, 286, 390, 406, 422, 454, 459, 646, 830, 869, 1015, 1070, 1120, 1518, 1528, 1710, 1742, 1870, 2670, 2871, 3586, 3654, 4394, 5070, 5214, 6102, 6446, 6692, 7295, 7943, 8339, 9204, 10664 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..218 (all terms up to 5 million)
MATHEMATICA
Select[Range[11000], Divisible[DivisorSigma[1, #]+DivisorSigma[1, #+1], EulerPhi[ #]]&] (* Harvey P. Dale, Jul 16 2018 *)
CROSSREFS
Sequence in context: A285971 A079418 A298170 * A370866 A184420 A136496
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Feb 20 2002
EXTENSIONS
First two terms prepended by Harvey P. Dale, Jul 16 2018
STATUS
approved

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Last modified June 15 18:41 EDT 2024. Contains 373410 sequences. (Running on oeis4.)