A244949 Least number k > n such that k^64 + n^64 is prime.

102, 37, 32, 39, 118, 13, 16, 11, 154, 41, 94, 29, 158, 17, 64, 291, 70, 107, 66, 63, 58, 87, 38, 397, 282, 69, 32, 129, 142, 67, 210, 87, 200, 227, 82, 55, 70, 137, 388, 541, 140, 103, 64, 167, 286, 71, 60, 593, 262, 459, 62, 69, 92, 91, 128, 81, 98, 149, 164, 107, 192, 103

Offset: 1

Author

Derek Orr, Jul 08 2014

Keywords

• nonn

Comments

a(n) = n+1 iff n is in A174157.

Examples

			8^64 + 11^64 = 4457915690803004131256192897205630962697827851093882159977969339137 is prime. Since 8^64 + 10^64 and 8^64 + 9^64 are both composite, a(8) = 11.
		

Links

• Jens Kruse Andersen, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A158979, A089489, A242556.

Programs

PARI

a(n)=for(k=n+1,10^4,if(isprime(k^64+n^64),return(k)))
n=1;while(n<100,print1(a(n),", ");n++)

Python

import sympy
from sympy import isprime
def a(n):
  for k in range(n+1,10**4):
    if isprime(k**64+n**64):
      return k
n = 1
while n < 100:
  print(a(n),end=', ')
  n += 1