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A110597 Balanced numbers (A020492) k such that k mod 12 = 1. 1
1, 1045, 29029, 50065, 64285, 87685, 1390753, 2011009, 3189625, 7711405, 39298441, 53238625, 68393065, 75416341, 96345613, 225938245, 228404605, 231562825, 233591605, 279999445, 458406445, 462027565, 470527057, 491291125, 513574369, 663605761, 666373825 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

For the first 27 terms, the quotient sigma(n)/phi(n) is 1, 2 or 3.

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..8224 (terms below 6.5*10^14, calculated using data from Jud McCranie)

MAPLE

with(numtheory); BNM1:=[]: for z from 1 to 1 do for m from 0 to 500000 do n:=12*m+1; if sigma(n) mod phi(n) = 0 then BNM1:=[op(BNM1), n] fi; od; od; BNM1;

MATHEMATICA

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

PROG

(PARI) forstep(n=1, 1e5, 12, if(sigma(n)%eulerphi(n)==0, print1(n", "))) \\ Charles R Greathouse IV, Nov 27 2013

CROSSREFS

Intersection of A017533 and A020492.

Cf. A000010, A000203, A062699.

Sequence in context: A344376 A023067 A344410 * A258130 A226114 A249653

Adjacent sequences:  A110594 A110595 A110596 * A110598 A110599 A110600

KEYWORD

nonn

AUTHOR

Walter Kehowski, Sep 13 2005

EXTENSIONS

a(10)-a(27) from Donovan Johnson, Aug 30 2012

STATUS

approved

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Last modified June 12 16:05 EDT 2021. Contains 344959 sequences. (Running on oeis4.)