A015792 Numbers k such that phi(k) + 3 | sigma(k).

12, 126, 152, 216, 245, 392, 490, 63872, 259856, 16750592, 4294541312

Offset

1,1

Comments

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

Links

Table of n, a(n) for n=1..11.

Mathematica

Select[Range[100000],
Divisible[DivisorSigma[1, #], EulerPhi[#] + 3] &] (* David Nacin, Feb 28 2012 *)

Crossrefs

Sequence in context: A178626 A223322 A061114 * A343769 A348463 A159736

Adjacent sequences: A015789 A015790 A015791 * A015793 A015794 A015795

Keyword

nonn

Author

Robert G. Wilson v

Extensions

Offset corrected and a(8)-a(11) from Donovan Johnson, Feb 28 2012

Status

approved