|
|
A304856
|
|
Numbers k such that prime(k)^k - 2 is prime.
|
|
1
|
|
|
2, 4, 18, 19, 20, 21, 31, 38, 82, 94, 212
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
a(12) > 10000, if it exists.
|
|
LINKS
|
|
|
EXAMPLE
|
2 is in the sequence because prime(2)^2 - 2 = 3^2 - 2 = 7.
|
|
MAPLE
|
N:=10000:
for X from 1 to N do
if isprime(ithprime(X)^X - 2) then print(X);
end if:
end do:
|
|
MATHEMATICA
|
Select[Range[220], PrimeQ[Prime[#]^#-2]&] (* Harvey P. Dale, Apr 03 2019 *)
|
|
PROG
|
(PARI) select( is(n)=ispseudoprime(prime(n)^n-2), [1..222]) \\ M. F. Hasler, May 21 2018
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,more
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|