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A067733 Numbers n such that phi(prime(n)-1)==0 (mod n). 0
1, 12, 540, 1024, 1072, 1092, 1320, 1408, 4272, 16200, 29568, 40082, 43740, 56592, 123192, 251736, 265440, 276000, 664320, 725760, 758560, 771264, 2101248 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

MATHEMATICA

Select[Range[42000], Mod[EulerPhi[Prime[ # ] - 1], # ] == 0 &]

PROG

(PARI) for(k=1, 2600000, if(eulerphi(prime(k)-1)%k==0, print1(k, ", ")))

CROSSREFS

Sequence in context: A198056 A004801 A202079 * A184423 A064344 A163046

Adjacent sequences:  A067730 A067731 A067732 * A067734 A067735 A067736

KEYWORD

nonn

AUTHOR

Benoit Cloitre (benoit7848c(AT)orange.fr), Feb 05 2002

EXTENSIONS

More terms from Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Feb 13 2002

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Last modified February 16 23:43 EST 2012. Contains 205978 sequences.