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 A049408 #16 Sep 08 2022 08:44:58 %S A049408 1,2,5,6,9,11,12,14,24,26,32,36,44,47,60,69,72,74,77,89,90,102,107, %T A049408 119,126,131,146,147,159,162,170,171,186,191,197,204,206,219,239,240, %U A049408 252,266,284,285,290,296,300,324,347,351,362,384,426,437,459,465,470 %N A049408 Numbers k such that k^4 + k + 1 is prime. %C A049408 For s = 5,8,11,14,17,20,..., n_s = 1 + n + n^s is always composite for any n > 1. Also for n=1, n_s=3 is a prime for any s. Here we consider the case s=4. %H A049408 T. D. Noe, <a href="/A049408/b049408.txt">Table of n, a(n) for n = 1..1000</a> %e A049408 26 is a term because at s=4, n=26, n_s = 1 + n + n^s = 457003 is a prime. %t A049408 Select[Range[1000], PrimeQ[1 + # + #^4] &] (* _Vincenzo Librandi_, Jul 28 2014 *) %o A049408 (PARI) for(n=1, 1000, if(isprime(1+n+n^4), print1(n","))) %o A049408 (Magma) [n: n in [0..1000] | IsPrime(s) where s is 1+n+n^4]; // _Vincenzo Librandi_, Jul 28 2014 %Y A049408 Cf. A002384, A075723, A049407. %K A049408 nonn,easy %O A049408 1,2 %A A049408 _N. J. A. Sloane_