A110599 Balanced numbers n such that n mod 12 = 7.

24871, 58435, 140335, 1529983, 2086903, 3722875, 3830827, 8697535, 13932919, 16408315, 21578755, 27882595, 76319155, 126245119, 183531439, 192871987, 198394675, 207619555, 229523371, 337800463, 361504507, 416690995, 440127655, 535044055, 693298315, 729802255

Offset: 1

Author

Walter Kehowski, Sep 13 2005

Keywords

• nonn

Comments

For the first 26 terms, the quotient (sigma(n)/phi(n)) is 2 or 3.

Links

• Amiram Eldar, Table of n, a(n) for n = 1..7901 (terms below 6.5*10^14, calculated using data from Jud McCranie)

Crossrefs

Intersection of A017605 and A020492.

Cf. A000010, A000203, A062699.

Programs

Maple

with(numtheory); BNM7:=[]: for z from 1 to 1 do for m from 1 to 1000000 do n:=12*m+7; if sigma(n) mod phi(n) = 0 then BNM7:=[op(BNM7),n] fi; od; od; BNM7;

Mathematica

Select[Range[10^7], Mod[#, 12] == 7 && Divisible[DivisorSigma[1, #], EulerPhi[#]] &] (* Amiram Eldar, Dec 04 2019 *)

Extensions

Duplicate terms removed and a(8)-a(26) from Donovan Johnson, Aug 30 2012