

A137715


Prime values of n for which n*2^k + 1 is composite for all positive integers k.


5



271129, 322523, 327739, 482719, 934909, 1639459, 2131043, 2131099, 2576089, 3098059, 3608251, 4573999, 6678713, 6799831, 7523281, 7761437, 8184977, 8840599, 8879993, 8959163, 9208337, 9252323, 9930469, 9937637, 10192733, 10306187, 10391933, 11206501
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OFFSET

1,1


COMMENTS

The sequence contains those members of A076336 that are prime.


LINKS

R. Baillie, G. Cormack, and H. C. Williams, The Problem of Sierpinski Concerning k*2^n+1, Mathematics of Computation, Vol. 37, No. 155 (July 1981), pp. 229231. Corrigenda; Mathematics of Computation, Vol. 39, No. 159 (July 1982), p. 308.


EXAMPLE

As 271129 is the first known prime value of n for which n*2^k + 1 is composite for all positive integers k, a(1) = 271129.


CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS



STATUS

approved



