A050808 Numbers k such that floor(exp(k)) is prime.

1, 2, 18, 50, 127, 141, 267, 310, 2290, 4487, 5391, 14025

Offset

1,2

Links

Table of n, a(n) for n=1..12.

Eric Weisstein's World of Mathematics, e-Prime

Mathematica

Do[ If[ PrimeQ[ Floor[ \[ExponentialE]^n] ], Print[n] ], {n, 0, 4750} ]
Select[Range[15000], PrimeQ[Floor[Exp[#]]]&] (* Harvey P. Dale, Oct 16 2012 *)

Prog

(PARI) is(n)=ispseudoprime(exp(n)\1) \\ Charles R Greathouse IV, Jan 03 2014

Crossrefs

Cf. A050809 (the actual primes), A000149, A040016, A037028, A000227, A004791, A059791, A059792.

Sequence in context: A048910 A356712 A077591 * A058653 A058794 A114109

Adjacent sequences: A050805 A050806 A050807 * A050809 A050810 A050811

Keyword

nonn,hard,more

Author

Patrick De Geest, Oct 15 1999

Extensions

Corrected by Naohiro Nomoto, Feb 22 2001

More terms from Vladeta Jovovic, Feb 24 2001

More terms from Robert G. Wilson v, May 09 2001

a(11) = 5391 from Eric W. Weisstein, May 01 2006

a(12) from Donovan Johnson, Feb 04 2008

Status

approved