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 A086983 Primes of the form 2^r*p^s - 1, where p is an odd prime. 1
 2, 3, 5, 7, 11, 13, 17, 19, 23, 31, 37, 43, 47, 53, 61, 67, 71, 73, 79, 97, 103, 107, 127, 151, 157, 163, 191, 193, 199, 211, 223, 241, 271, 277, 283, 313, 331, 337, 367, 383, 397, 421, 431, 457, 463, 487, 499, 523, 541, 547, 577, 607, 613, 631, 647, 661, 673 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes p such that p+1 has at most one odd prime divisor. LINKS Robert Israel, Table of n, a(n) for n = 1..10000 MAPLE N:= 1000: # to get all terms <= N Primes:= select(isprime, [\$3..(N+1)/2]): sort(convert(select(isprime, {2, seq(seq(seq(2^r*p^s-1, r = 1 .. ilog2((N+1)/p^s)), s=0..floor(log[p]((N+1)/2))), p=Primes)}), list)); # Robert Israel, Jun 13 2018 CROSSREFS Cf. A005105, A077497, A077498, A077499, A077500. Cf. also A005109, A077313, A077314, A077315. Sequence in context: A128898 A006514 A216286 * A303436 A334797 A229060 Adjacent sequences: A086980 A086981 A086982 * A086984 A086985 A086986 KEYWORD nonn AUTHOR Ray Chandler, Aug 02 2003 STATUS approved

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Last modified April 23 08:14 EDT 2024. Contains 371905 sequences. (Running on oeis4.)