OFFSET
1,1
COMMENTS
If x is allowed to be negative, then a(1) = 1^-1 + 2^0 = 2. - Jason Yuen, Sep 21 2024
EXAMPLE
a(1) = 3 because x = 0 produces the prime 1^0+2^1 = 3;
a(16) = 49814113380273715457 because x < 15 produces composites and x = 15 produces the prime 16^15+17^16 = 49814113380273715457.
PROG
(PARI) a(n)=my(p); for(x=0, oo, p=n^x+(n+1)^(x+1); if(isprime(p), return(p))) \\ Jason Yuen, Sep 21 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Tomas Xordan, Jun 02 2007
STATUS
approved