A015801 Numbers k such that phi(k) + 10 | sigma(k).

6, 12, 30, 68, 96, 264, 368, 2064, 4240, 4636, 6588, 7276, 10272, 11800, 36600, 188544, 251648, 415000, 1296640, 3113472, 50202624, 201068544, 16097947360, 17177182208, 25876667904, 85895741440

Offset: 1

Author

Robert G. Wilson v

Keywords

• nonn

Comments

a(27) > 10^12. - Donovan Johnson, Feb 28 2012

Crossrefs

Cf. A000010, A000203.

Programs

Mathematica

Select[Range[1000000],Divisible[DivisorSigma[1,#],EulerPhi[#]+10]&] (* Harvey P. Dale, Jul 17 2011 *)

Extensions

More terms from Harvey P. Dale, Jul 17 2011

Offset corrected and a(19)-a(26) from Donovan Johnson, Feb 28 2012