cp's OEIS Frontend

A244932 Least number k > n such that k^8 + n^8 is prime.

%I A244932 #11 May 22 2025 10:21:39
%S A244932 2,13,10,17,6,37,12,13,16,27,24,71,16,31,64,43,18,43,26,23,32,29,24,
%T A244932 79,32,53,34,61,92,47,40,33,34,57,36,47,40,53,40,79,44,43,68,91,68,57,
%U A244932 66,61,60,53,58,83,60,91,94,61,82,61,70,101,82,71,68,145,82,67,76,69,100
%N A244932 Least number k > n such that k^8 + n^8 is prime.
%C A244932 a(n) = n+1 iff n is in A153504.
%H A244932 Jens Kruse Andersen, <a href="/A244932/b244932.txt">Table of n, a(n) for n = 1..10000</a>
%e A244932 13^8 + 14^8 = 2291519777 is not prime, 13^8 + 15^8 = 3378621346 is not prime. 13^8 + 16^8 = 5110698017 is prime. Thus a(13) = 16.
%o A244932 (Python)
%o A244932 import sympy
%o A244932 from sympy import isprime
%o A244932 def a(n):
%o A244932   for k in range(n+1,10**4):
%o A244932     if isprime(k**8+n**8):
%o A244932       return k
%o A244932 n = 1
%o A244932 while n < 100:
%o A244932   print(a(n),end=', ')
%o A244932   n += 1
%o A244932 (PARI) a(n)=for(k=n+1,10^4,if(isprime(k^8+n^8),return(k)))
%o A244932 n=1;while(n<100,print1(a(n),", ");n++)
%Y A244932 Cf. A158979, A089489, A242553.
%K A244932 nonn
%O A244932 1,1
%A A244932 _Derek Orr_, Jul 08 2014