

A092873


Prime factors of the odd terms of A007755.


4



3, 5, 11, 17, 41, 83, 137, 257, 641, 1097, 17477, 65537, 140417, 557057, 2384897, 4227137, 35946497, 71304257, 541073537, 2281701377, 2336497860617, 600470787982337, 2278291849363457, 4538923050090497, 38280596832649217
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OFFSET

1,1


COMMENTS

Catlin shows that if A007755(n) is odd and composite, then its factors are among the A007755(k), k < n. Note that the five Fermat primes are in this sequence.


LINKS



CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS

a(21) corrected and comment deleted by T. D. Noe, Nov 18 2008


STATUS

approved



