This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A383237 #11 Apr 24 2025 13:22:49 %S A383237 2,29,41,47,71,131,179,197,233,239,257,269,311,353,443,461,491,509, %T A383237 587,647,653,683,761,857,863,887,929,947,1013,1061,1223,1277,1283, %U A383237 1289,1301,1361,1373,1409,1427,1439,1499,1511,1559,1619,1637,1733,1823,1973,1979 %N A383237 Primes p such that x^5+x+1 has no roots modulo p. %C A383237 Every term is congruent to 2 modulo 3, hence, except for a(1) = 2, to 5 modulo 6. %H A383237 Jayde S. Massmann, <a href="/A383237/b383237.txt">Table of n, a(n) for n = 1..1000</a> %e A383237 a(1) = 2 because 0^5+0+1 = 1 and 1^5+1+1 = 3; neither is 0 mod 2. %e A383237 a(2) = 29, as for p = 3, 5, 7, 11, 13, 17, 19, 23, x^5+x+1 has a root modulo p, namely 1, 2, 2, 9, 3, 10, 3, 15, respectively. %o A383237 (PARI) isok(p) = if (isprime(p), !#polrootsmod(x^5+x+1, p)); \\ _Michel Marcus_, Apr 20 2025 %Y A383237 Subsequence of A003627. %K A383237 nonn %O A383237 1,1 %A A383237 _Jayde S. Massmann_, Apr 20 2025