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 A230378 #24 Mar 30 2022 07:54:44 %S A230378 71,13993643,19152352117,227633407,813955076015309926319, %T A230378 4098986195943739,46959719470144429555105032871, %U A230378 491873569944394295636860313807677,1848593595048531176470116001230356265643249547,108685909290746311448943506365699 %N A230378 The right Aurifeuillian factor of k^k - 1 for k congruent to 1 (mod 4) and squarefree. %C A230378 The values of k are given by A005117, except for the leading 1. %H A230378 Richard P. Brent, <a href="http://arxiv.org/abs/1004.5466">On computing factors of cyclotomic polynomials</a>, arXiv:1004.5466 [math.NT], 2010. %e A230378 13993643 is in the sequence because it is an Aurifeuillian factor of 13^13-1. %Y A230378 Cf. A005117, A220983, A220984, A230375-A230377, A230376. %K A230378 nonn %O A230378 1,1 %A A230378 _Colin Barker_, Oct 17 2013