A015788 Numbers k such that phi(k) + 9 | sigma(k + 9).

65, 88, 104, 127, 184, 189, 232, 248, 328, 344, 424, 568, 584, 632, 664, 872, 1192, 1208, 1247, 1544, 1592, 1688, 1864, 2008, 2104, 2152, 2264, 2648, 2792, 2824, 3032, 3112, 3208, 3352, 3448, 3681, 3688, 3992, 4168, 4328, 4504, 4552

Offset

1,1

Links

Table of n, a(n) for n=1..42.

Mathematica

Select[Range[4600], ivisible[DivisorSigma[1, # + 9], EulerPhi[#] + 9] &] (* Amiram Eldar, Dec 10 2018 *)

Crossrefs

Cf. A015775, A015781, A015782, A015783, A015784, A015785, A015786.

Sequence in context: A034071 A298380 A299247 * A072053 A336331 A160055

Adjacent sequences: A015785 A015786 A015787 * A015789 A015790 A015791

Keyword

nonn

Author

Robert G. Wilson v

Extensions

Incorrect a(1)=1 removed and title corrected by Sean A. Irvine, Dec 10 2018

Status

approved