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 A071565 #9 Aug 21 2021 22:00:42 %S A071565 4,10,12,16,22,40,60,66,70,78,88,96,100,106,126,150,162,172,178,210, %T A071565 228,238,240,256,262,268,292,346,348,358,378,396,430,432,442,460,490, %U A071565 498,508,520,546,576,592,598,600,630,658,676,682,732,738,742,760,772 %N A071565 Numbers k such that x^k + x^(k-1) + x^(k-2) + ... + x + 1 is irreducible over GF(7). %F A071565 a(n) = A019337(n+1) - 1. - _Joerg Arndt_, Apr 17 2020 %Y A071565 Cf. A071642. %Y A071565 Cf. A019337. - _Joerg Arndt_, Apr 17 2020 %K A071565 easy,nonn %O A071565 1,1 %A A071565 _Robert G. Wilson v_, Jun 22 2002