

A109602


Numbers n such that n!/(pi(n)!*2^n)+1 is prime.


0



1, 4, 5, 6, 7, 8, 9, 19, 20, 29, 31, 97, 113, 181, 286, 419, 485, 670, 1216
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OFFSET

1,2


COMMENTS

Next term, if it exists, is > 3000.  Ray Chandler, Aug 04 2005


LINKS



MATHEMATICA

f[n_] := n!/Fold[Times, 1, Range[PrimePi[n]]]*2^n + 1; Do[ If[ PrimeQ[ f[n]], Print[n]], {n, 1000}]


CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS



STATUS

approved



