login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A050808 Numbers n such that floor(exp(n)) is prime. 5
1, 2, 18, 50, 127, 141, 267, 310, 2290, 4487, 5391, 14025 (list; graph; refs; listen; history; text; internal format)
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: A223469 A048910 A077591 * A058653 A058794 A114109

Adjacent sequences:  A050805 A050806 A050807 * A050809 A050810 A050811

KEYWORD

nonn,hard

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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 20 17:54 EDT 2019. Contains 322310 sequences. (Running on oeis4.)