A242556 Least number k such that k^64 + n^64 is prime.

1, 37, 32, 39, 118, 13, 16, 11, 154, 41, 8, 29, 6, 17, 64, 7, 14, 107, 66, 63, 58, 87, 38, 397, 282, 69, 32, 129, 12, 67, 210, 3, 200, 227, 82, 55, 2, 7, 4, 541, 10, 103, 64, 167, 286, 71, 60, 593, 6, 459, 14, 3, 2, 91, 4, 81, 98, 21, 164, 47, 36, 51, 10, 15, 84, 19, 30

Offset: 1

Author

Derek Orr, May 17 2014

Keywords

• nonn

Comments

If a(n) = 1, then n is in A006316.

Crossrefs

Cf. A069003, A006316.

Programs

Mathematica

lnk[n_]:=Module[{c=n^64,k=1},While[!PrimeQ[c+k^64],k++];k]; Array[lnk,70] (* Harvey P. Dale, Oct 21 2017 *)

PARI

a(n)=for(k=1,oo,if(ispseudoprime(n^64+k^64),return(k)));

Python

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