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A067204
Numbers k such that sigma(sigma(k)) == phi(k) (mod sigma(k)).
1
2, 26, 77, 85, 194, 335, 707, 1350, 2443, 2639, 9158, 9602, 15238, 16625, 19698, 23199, 24416, 52328, 54663, 56927, 64206, 67226, 69875, 82235, 100837, 104489, 136213, 150040, 161268, 230216, 244572, 251488, 271215, 273208, 283492, 298205, 306878, 352660
OFFSET
1,1
LINKS
PROG
(PARI) for(n=1, 10^8, s=sigma(n); if(sigma(s)%s==eulerphi(n), print(n))) \\ Donovan Johnson, Feb 25 2013
CROSSREFS
Sequence in context: A345693 A229573 A337396 * A202077 A280212 A120551
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Feb 19 2002
STATUS
approved