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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; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..23.

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: A296685 A281030 A282589 * A285748 A184423 A064344

Adjacent sequences:  A067730 A067731 A067732 * A067734 A067735 A067736

KEYWORD

nonn

AUTHOR

Benoit Cloitre, Feb 05 2002

EXTENSIONS

More terms from Klaus Brockhaus, Feb 13 2002

STATUS

approved

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Last modified June 25 08:21 EDT 2019. Contains 324347 sequences. (Running on oeis4.)