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A290184
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Numbers k such that k mod phi(k) = lambda(k).
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1
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20, 42, 100, 156, 272, 294, 342, 500, 660, 780, 1332, 1980, 2028, 2058, 2500, 3900, 4624, 5256, 5940, 6498, 7260, 9312, 10140, 11772, 12500, 14406, 17820, 19500, 21780, 26364, 26406, 37056, 49284, 50700, 53460, 62244, 62500, 65340, 65792, 78608, 79860, 97500
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OFFSET
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1,1
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COMMENTS
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Numbers k such that A068494(k) = A002322(k).
If k is in the sequence, then k*gpf(k) is in the sequence.
Are there infinitely many terms of the form (p-1)*p, where p is a prime?
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LINKS
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Robert Israel, Table of n, a(n) for n = 1..184
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MAPLE
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select(n -> n mod numtheory:-phi(n) = numtheory:-lambda(n), [seq(i, i=2..100000, 2)]); # Robert Israel, Aug 04 2017
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MATHEMATICA
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Select[Range[10^5], Mod[#, EulerPhi@ #] == CarmichaelLambda@ # &] (* Michael De Vlieger, Jul 23 2017 *)
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PROG
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(PARI) isok(n) = (n % eulerphi(n)) == lcm(znstar(n)[2]); \\ Michel Marcus, Jul 23 2017
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CROSSREFS
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Subsequence of A124240.
Cf. A000010, A002322, A068494.
Sequence in context: A075228 A256102 A128672 * A126251 A100515 A220006
Adjacent sequences: A290181 A290182 A290183 * A290185 A290186 A290187
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KEYWORD
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nonn
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AUTHOR
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Thomas Ordowski, Jul 23 2017
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EXTENSIONS
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More terms from Robert Israel, Jul 23 2017
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STATUS
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approved
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