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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A249570 Conjectured values of least number k such that k^k + n^n is prime, or 0 if no such k exists. 1
1, 1, 2, 1, 0, 25, 2, 157, 0, 7, 48, 23, 40, 3, 4, 25, 0, 7, 70, 31, 74, 57, 12, 203, 4, 945, 14, 33, 0, 0, 20, 93, 28, 193, 2442, 0, 728, 183, 70, 13, 0, 0, 2, 13, 0, 0, 0, 11, 0, 0, 0, 0, 0, 0, 14, 0, 22, 0, 0, 0, 72, 109, 0, 85, 0, 73, 0, 0, 0, 19, 0, 61, 12, 21, 4, 0, 570, 0, 0, 177, 1532, 0, 0, 55, 64, 75, 602, 151, 0, 133, 0, 0, 32, 33, 3786, 0, 122, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

The zero entries are only conjectural.

a(5) > 10000 or 0. Other a(n) = 0 entries have been checked up to k = 7500.

If a(i) = j, then a(j) <= i.

LINKS

Table of n, a(n) for n=1..99.

PROG

(PARI) a(n)=k=1; while(!ispseudoprime(k^k+n^n), k++); k

CROSSREFS

Sequence in context: A009829 A202697 A268436 * A051652 A077019 A139037

Adjacent sequences:  A249567 A249568 A249569 * A249571 A249572 A249573

KEYWORD

nonn,hard,more

AUTHOR

Derek Orr, Nov 01 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 May 23 13:25 EDT 2019. Contains 323514 sequences. (Running on oeis4.)