A015851 Numbers k such that phi(k) | sigma(k + 8).

1, 2, 3, 4, 6, 7, 9, 11, 14, 15, 18, 20, 34, 36, 38, 39, 52, 63, 70, 84, 85, 97, 100, 111, 116, 130, 146, 150, 153, 162, 174, 180, 182, 196, 207, 216, 220, 222, 231, 247, 372, 427, 429, 468, 490, 505, 507, 608, 612, 700, 702, 741, 742, 748, 775, 855, 861

Offset: 1

Author

Robert G. Wilson v

Keywords

• nonn

Programs

Mathematica

Select[Range[1, 999], Divisible[DivisorSigma[1, 8 + #], EulerPhi[#]] &] (* David Nacin, Mar 04 2012 *)

PARI

is(n)=!(sigma(n+8)%eulerphi(n)) \\ Charles R Greathouse IV, Sep 25 2012