A086983 Primes of the form 2^r*p^s - 1, where p is an odd prime.

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

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