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 A109349 #13 Feb 16 2025 08:32:58 %S A109349 2,3,109,37,6841,13,372709,1513,176149,1661,964249309,1801, %T A109349 47834153641,75139,3162961,3077713,115933787267041,30133, %U A109349 5689910849522509,3949201,6868494361,168846239,13678413205562919109,4654801,97995219736887001 %N A109349 Zsigmondy numbers for a = 7, b = 5: Zs(n, 7, 5) is the greatest divisor of 7^n - 5^n that is relatively prime to 7^m - 5^m for all positive integers m < n. %H A109349 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ZsigmondyTheorem.html">Zsigmondy's Theorem</a> %Y A109349 Cf. A064078-A064083, A109325, A109347, A109348. %K A109349 nonn %O A109349 1,1 %A A109349 _Jonathan Vos Post_, Aug 21 2005 %E A109349 Edited, corrected and extended by _Ray Chandler_, Aug 26 2005 %E A109349 Definition corrected by _Jerry Metzger_, Nov 04 2009