login
A015788
Numbers k such that phi(k) + 9 | sigma(k + 9).
2
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
MATHEMATICA
Select[Range[4600], Divisible[DivisorSigma[1, # + 9], EulerPhi[#] + 9] &] (* Amiram Eldar, Dec 10 2018 *)
KEYWORD
nonn
EXTENSIONS
Incorrect a(1)=1 removed and title corrected by Sean A. Irvine, Dec 10 2018
STATUS
approved