A110598 Balanced numbers k such that k mod 12 = 5.

137885, 145145, 3501605, 6605945, 6953765, 8409305, 10055045, 11413205, 11569805, 16540205, 18545285, 19648805, 21902705, 22806905, 25965005, 26655005, 29811665, 45680921, 71569745, 79989845, 91681289, 196492205, 214218389, 223086125, 229554941, 233601641

Offset: 1

Author

Walter Kehowski, Sep 13 2005

Keywords

• nonn

Comments

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

Links

• Amiram Eldar, Table of n, a(n) for n = 1..7013 (terms below 6.5*10^14, calculated using data from Jud McCranie)

Crossrefs

Intersection of A017581 and A020492.

Cf. A000010, A000203, A062699, A068391.

Programs

Maple

with(numtheory); BNM5:=[]: for z from 1 to 1 do for m from 1 to 1000000 do n:=12*m+5; if sigma(n) mod phi(n) = 0 then BNM5:=[op(BNM5),n] fi; od; od; BNM5;

Mathematica

Select[Range[5,12000000,12],MemberQ[{2,3},DivisorSigma[1,#]/EulerPhi[#]]&]  (* Harvey P. Dale, May 06 2012 *)

Extensions

a(10)-a(26) from Donovan Johnson, Aug 30 2012