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 A001271 #41 Sep 15 2023 04:22:34 %S A001271 2,11,101,7,11,13,73,137,11,9091,101,9901,11,909091,17,5882353,7,11, %T A001271 13,19,52579,101,3541,27961,11,11,23,4093,8779,73,137,99990001,11,859, %U A001271 1058313049,29,101,281,121499449,7,11,13,211,241,2161,9091,353,449,641,1409,69857 %N A001271 Irregular table read by rows: row n lists prime factors of 10^n +1, with multiplicity. %C A001271 Except for 2, all these primes are in A028416, and all the primes in A028416 appear here. - _Davide Rotondo_, Aug 12 2023 %D A001271 J. Brillhart et al., Factorizations of b^n +- 1. Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 2nd edition, 1985; and later supplements. %H A001271 Ray Chandler, <a href="/A001271/b001271.txt">Rows n=0..310, flattened</a> (from Kamada link) %H A001271 J. Brillhart et al., <a href="http://dx.doi.org/10.1090/conm/022">Factorizations of b^n +- 1</a>, Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 3rd edition, 2002. %H A001271 Makoto Kamada, <a href="https://stdkmd.net/nrr/repunit/10001.htm">Factorizations of 100...001</a>. %H A001271 S. S. Wagstaff, Jr., <a href="http://www.cerias.purdue.edu/homes/ssw/cun/index.html">The Cunningham Project</a> %e A001271 Table begins: %e A001271 2; %e A001271 11; %e A001271 101, %e A001271 7, 11, 13; %e A001271 73, 137; %e A001271 11, 9091; %e A001271 101, 9901; %e A001271 11, 909091; %e A001271 17, 5882353; %e A001271 ... %Y A001271 Cf. A028416, A057934, A062397. %K A001271 nonn,tabf %O A001271 0,1 %A A001271 _N. J. A. Sloane_, revised Jul 13 2009 %E A001271 Term ordering corrected by _Sean A. Irvine_, Apr 11 2012 %E A001271 Minor edits to description by _Ray Chandler_, May 02 2017