A247228 Prime numbers p where 2^p-1 is composite that set records for smallest prime factor of 2^p-1: the smallest prime factor of 2^p-1 is larger than the smallest prime factor of 2^q-1 for all primes q > p.
11, 23, 29, 41, 59, 67, 101, 137, 149, 293, 523
Offset: 1
Examples
12 is not in the sequence because 12 is not prime. 13 is not in the sequence because 2^13-1 is prime. 37 is not in the sequence because while the smallest prime factor of 2^29-1 is 233, the smallest prime factor of 2^37-1 is only 223.
Crossrefs
Cf. A054723.
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