A110599 - OEIS

%I #11 Dec 04 2019 11:40:56

%S 24871,58435,140335,1529983,2086903,3722875,3830827,8697535,13932919,

%T 16408315,21578755,27882595,76319155,126245119,183531439,192871987,

%U 198394675,207619555,229523371,337800463,361504507,416690995,440127655,535044055,693298315,729802255

%N Balanced numbers n such that n mod 12 = 7.

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

%H Amiram Eldar, <a href="/A110599/b110599.txt">Table of n, a(n) for n = 1..7901</a> (terms below 6.5*10^14, calculated using data from Jud McCranie)

%p 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;

%t Select[Range[10^7], Mod[#, 12] == 7 && Divisible[DivisorSigma[1, #], EulerPhi[#]] &] (* _Amiram Eldar_, Dec 04 2019 *)

%Y Intersection of A017605 and A020492.

%Y Cf. A000010, A000203, A062699.

%K nonn

%O 1,1

%A _Walter Kehowski_, Sep 13 2005

%E Duplicate terms removed and a(8)-a(26) from _Donovan Johnson_, Aug 30 2012