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 A219117 #6 Dec 15 2017 23:20:15 %S A219117 1,2,5,6,69,131,426,1665,2129,2696,5250,7929,9689,13545,14154,14286, %T A219117 16434,19760,25739,27809,29631,36821,41819,46619,48321,59030,60500, %U A219117 61955,62321,73610,77685,79646,80535,82655,85251,86996,91014,96566,97739,105939,108240 %N A219117 Numbers n such that n^1+n+1, n^2+n+1, n^3+n+1 and n^4+n+1 are all prime. %H A219117 Robert Israel, <a href="/A219117/b219117.txt">Table of n, a(n) for n = 1..1000</a> %p A219117 select(t -> andmap(isprime, [2*t+1,t^2+t+1,t^3+t+1,t^4+t+1]), [$1..2*10^5]); # _Robert Israel_, Dec 15 2017 %o A219117 (Haskell) %o A219117 a219117_list = filter (all (== 1) . p) [1..] where %o A219117 p x = map (a010051 . (+ (x + 1)) . (x ^)) [1..4] %Y A219117 Cf. A057683 (subsequence); A010051. %K A219117 nonn %O A219117 1,2 %A A219117 _Reinhard Zumkeller_, Nov 12 2012