OFFSET
1,3
COMMENTS
If a(n) = 1, then n is in A006313.
EXAMPLE
4^16+1^16 = 4294967297 is not prime. 4^16+2^16 = 4295032832 is not prime. 4^16+3^16 = 4338014017 is prime. Thus, a(4) = 3.
PROG
(Python)
import sympy
from sympy import isprime
def a(n):
for k in range(10**4):
if isprime(n**16+k**16):
return k
n = 1
while n < 100:
print(a(n))
n += 1
(PARI) a(n)=for(k=1, oo, if(ispseudoprime(n^16+k^16), return(k)));
CROSSREFS
KEYWORD
nonn
AUTHOR
Derek Orr, May 17 2014
STATUS
approved