A015804 Numbers k such that phi(k) + 11 | sigma(k).

8, 25, 34, 50, 304, 432, 1700, 1968, 2400, 2656, 13504, 44736, 59776, 1025536, 4148224, 12512256, 16685056, 66924544, 201043968, 51535085568, 68713578496

Offset: 1

Author

Robert G. Wilson v

Keywords

• nonn

Comments

a(22) > 10^12. - Donovan Johnson, Feb 28 2012

Programs

Mathematica

Select[Range[100000],
Divisible[DivisorSigma[1, #], EulerPhi[#] + 11] &] (* David Nacin, Feb 28 2012 *)

Extensions

a(11)-a(21) from Donovan Johnson, Feb 28 2012