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 A015800 Numbers n such that phi(n) + 9 | sigma(n). 0
 26, 312, 828, 2475, 2520, 4950, 7412, 7942, 10464, 14454, 30952, 89262, 1029632, 3116544, 17721152, 56889152, 538655552, 804839424, 9287924224, 206150959104, 698155922432 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(22) > 10^12. - Donovan Johnson, Feb 28 2012 LINKS MATHEMATICA Cases[Range[100000], x_ /; Divisible[DivisorSigma[1, x], EulerPhi[x] + 9] == True] - David Nacin, Feb 28 2012 Select[Range[1000000], Divisible[DivisorSigma[1, #], EulerPhi[#]+9]&] (* Harvey P. Dale, May 24 2012 *) CROSSREFS Sequence in context: A014472 A000498 A066912 * A276285 A232064 A030647 Adjacent sequences:  A015797 A015798 A015799 * A015801 A015802 A015803 KEYWORD nonn AUTHOR EXTENSIONS a(9)-a(21) from Donovan Johnson, Feb 28 2012 STATUS approved

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Last modified January 16 19:49 EST 2019. Contains 319206 sequences. (Running on oeis4.)