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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
OFFSET
1,1
COMMENTS
Primes p such that p+1 has at most one odd prime divisor.
LINKS
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
KEYWORD
nonn
AUTHOR
Ray Chandler, Aug 02 2003
STATUS
approved