A015798 - OEIS

A015798

Numbers k such that phi(k) + 7 | sigma(k).

9, 18, 24, 408, 7684, 10848, 14528, 46272, 533776, 774912, 201142272, 1410521344, 3220488192, 4469373184, 6505814272, 27945013504

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

a(17) > 10^12. - Donovan Johnson, Feb 28 2012

LINKS

MATHEMATICA

Cases[Range[100000],

x_ /; Divisible[DivisorSigma[1, x], EulerPhi[x] + 7] == True] (* David Nacin, Feb 28 2012 *)

CROSSREFS

KEYWORD

nonn

AUTHOR

EXTENSIONS

Offset corrected and a(9)-a(16) from Donovan Johnson, Feb 28 2012

STATUS

approved