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A067932
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Primes p such that p+3 == 0 (mod phi(p+3)).
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1
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3, 5, 13, 29, 61, 509, 1021, 4093, 16381, 1048573, 4194301, 16777213, 536870909, 19807040628566084398385987581, 83076749736557242056487941267521533, 5316911983139663491615228241121378301
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OFFSET
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1,1
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COMMENTS
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phi(n) divides n iff n=1 or n=2^w*3^u for w>=1 and u>=0 (see A007694). Such an n can only have the form p+3 if n=6 or n is a power of 2. So the terms of the sequence are 3 and the primes of the form 2^n-3, listed in A050415.
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LINKS
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MATHEMATICA
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Prepend[Select[2^Range[2, 200]-3, PrimeQ], 3]
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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