A094786 Primes that are 2 less than a perfect power m^k, k >= 2.

2, 7, 23, 47, 79, 167, 223, 241, 359, 439, 727, 839, 1087, 1223, 1367, 1847, 2207, 2399, 3023, 3373, 3719, 3967, 4759, 5039, 5623, 5927, 6857, 7919, 8647, 10607, 11447, 13687, 14159, 14639, 16127, 17159, 18223, 19319, 19681, 21023, 24023, 25919

Offset

1,1

Links

Zak Seidov, Table of n, a(n) for n = 1..1000

Prog

(PARI) k(n, m) = forprime(x=2, n, if(ispower(x+m), print1(x", "))) ispower(n) = { local(p, r, j); r = sqrt(n); for(j=2, floor(r), p = floor(log(n)/log(j)+.5); if(j^p ==n, return(1)); ); return(0) }

Crossrefs

Cf. A001597 (perfect powers).

Sequence in context: A100917 A049552 A049572 * A028871 A053705 A247175

Adjacent sequences: A094783 A094784 A094785 * A094787 A094788 A094789

Keyword

nonn

Author

Cino Hilliard, Jun 10 2004

Extensions

Comment deleted by Zak Seidov, Apr 17 2013

Status

approved