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A015833 Numbers k such that phi(k + 13) | sigma(k). 1
5, 7, 15, 21, 23, 35, 47, 71, 77, 87, 132, 155, 191, 263, 295, 297, 310, 357, 359, 428, 431, 437, 479, 503, 527, 595, 638, 660, 719, 759, 790, 837, 839, 863, 983, 1002, 1105, 1151, 1155, 1223, 1269, 1336, 1376, 1463, 1495, 1511, 1512, 1559, 1615, 1817, 1871 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..2000

MATHEMATICA

Select[Range[3000], Divisible[DivisorSigma[1, #], EulerPhi[13 + #]] &] (* David Nacin, Mar 03 2012 *)

PROG

(PARI) is(n)=sigma(n)%(eulerphi(n)+13)==0 \\ Charles R Greathouse IV, Sep 25 2012

CROSSREFS

Sequence in context: A314366 A068580 A110994 * A072022 A003429 A076860

Adjacent sequences:  A015830 A015831 A015832 * A015834 A015835 A015836

KEYWORD

nonn

AUTHOR

Robert G. Wilson v

STATUS

approved

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Last modified May 24 18:34 EDT 2019. Contains 323534 sequences. (Running on oeis4.)