login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A057908 Numbers n such that 4^n - n is prime. 4
1, 3, 5, 35, 95, 1323, 24747 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(8) > 2*10^5. - Robert Price, Feb 11 2014

LINKS

Table of n, a(n) for n=1..7.

MATHEMATICA

Do[ If[ PrimeQ[ 4^n - n ], Print[ n ] ], {n, 0, 3000} ]

PROG

(PARI) for(k=1, 10^6, if(ispseudoprime(4^k-k), print1(k, ", "))); /* Joerg Arndt, Apr 07 2013 */

CROSSREFS

Sequence in context: A055786 A001790 A173092 * A120828 A077784 A325582

Adjacent sequences:  A057905 A057906 A057907 * A057909 A057910 A057911

KEYWORD

nonn,more

AUTHOR

Robert G. Wilson v, Nov 16 2000

EXTENSIONS

a(7) from Robert Price, Feb 11 2014

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 July 25 22:19 EDT 2021. Contains 346294 sequences. (Running on oeis4.)