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 A029757 #12 Sep 08 2022 08:44:50 %S A029757 0,1,1,5,1,21,9,45,225,357,761,1757,2641,5013,489,18829,28609,11973, %T A029757 59865,37181,185905,929525,2550473,4363757,13430177,42021,33764537, %U A029757 34604957,38807057,194035285,433305513 %N A029757 a(n) = 5^n mod 2^n. %H A029757 Vincenzo Librandi, <a href="/A029757/b029757.txt">Table of n, a(n) for n = 0..240</a> %p A029757 a:=n->5^n mod(2^(n)): seq(a(n), n=0..33); # _Zerinvary Lajos_, Feb 15 2008 %o A029757 (PARI) A029757(n) = lift(Mod(5^n,2^n)) \\ _Michael B. Porter_, Feb 02 2010 %o A029757 (Magma) [5^n mod 2^n: n in [0..80]]; // _Vincenzo Librandi_, Apr 25 2011 %K A029757 nonn,easy %O A029757 0,4 %A A029757 _N. J. A. Sloane_