Search: id:A140452 Results 1-1 of 1 results found. %I A140452 %S A140452 11,22,23,25,28,29,33 %N A140452 2^(a(n))-1 contains an overpseudoprime divisor. %C A140452 If p is a prime then p is in the sequence iff 2^p-1 is a composite number. %D A140452 V. Shevelev, Overpsudoprimes, Mersenne Numbers and Wieferich Primes, http://arxiv.org/abs/0806.3412 %Y A140452 Cf. A141232, A137576, A005420, A049479. %Y A140452 Sequence in context: A138838 A139337 A040110 this_sequence A048136 A166713 A095779 %Y A140452 Adjacent sequences: A140449 A140450 A140451 this_sequence A140453 A140454 A140455 %K A140452 nonn %O A140452 1,1 %A A140452 Vladimir Shevelev (shevelev(AT)bgu.ac.il), Jun 26 2008 Search completed in 0.001 seconds