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Primes of the form x^2 + y^8.
1

%I #14 Dec 07 2023 18:23:52

%S 2,5,17,37,101,197,257,281,337,401,577,617,677,881,1097,1217,1297,

%T 1481,1601,1777,2281,2657,2857,2917,3137,4357,4481,5297,5477,5881,

%U 6577,6661,6961,7057,7237,7481,7717,8101,8161,8537,8677,8837,9281,9697,10457,10657,12037

%N Primes of the form x^2 + y^8.

%C Merikoski proves that this sequence is infinite.

%H Alois P. Heinz, <a href="/A346809/b346809.txt">Table of n, a(n) for n = 1..10000</a>

%H Jori Merikoski, <a href="https://arxiv.org/abs/2108.01355">Exceptional characters and prime numbers in sparse sets</a>, arXiv:2108.01355 [math.NT], 2021.

%o (PARI) lista(lim)=my(v=List([2]), t); for(a=1, sqrtint(lim), forstep(b=a%2+1, sqrtnint(lim-a^2, 8), 2, t=a^2+b^8; if(isprime(t), listput(v, t)))); vecsort(Vec(v), , 8); \\ after A028916

%Y Cf. A002496 (a subsequence), A028916.

%K nonn

%O 1,1

%A _Michel Marcus_, Aug 05 2021