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 A100331 #21 Sep 08 2022 08:45:15
%S A100331 1,3,9,15,18,20,28,33,55,65,68,84,88,98,109,115,119,120,124,129,134,
%T A100331 135,140,159,165,173,185,188,190,205,223,239,264,270,275,278,288,295,
%U A100331 305,308,323,329,350,368,370,388,409,460,464,499,510,525,540,565,579,593
%N A100331 Positive integers n such that n^6 + n^5 + n^4 + n^3 + n^2 + n - 1 is prime.
%H A100331 Robert Israel, <a href="/A100331/b100331.txt">Table of n, a(n) for n = 1..10000</a>
%e A100331 3 is in the sequence because 3^6 + 3^5 + 3^4 + 3^3 + 3^2 + 3 - 1 = 1091, which is prime.
%p A100331 A100331:=n->`if`(isprime(-1+add(n^i, i=1..6)), n, NULL): seq(A100331(n), n=1..1000); # _Wesley Ivan Hurt_, Dec 13 2015
%t A100331 Select[Range[600], PrimeQ[Sum[ #^i, {i, 6}] - 1] &] (* _Ray Chandler_, Nov 17 2004 *)
%o A100331 (Magma) [n: n in [0..700] | IsPrime(n^6+n^5+n^4+n^3+n^2+n-1)]; // _Vincenzo Librandi_, Dec 13 2015
%o A100331 (PARI) is(n) = ispseudoprime(n^6+n^5+n^4+n^3+n^2+n-1) \\ _Altug Alkan_, Dec 13 2015
%Y A100331 Cf. A100330.
%K A100331 nonn,easy
%O A100331 1,2
%A A100331 _Ray G. Opao_, Nov 16 2004