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 A074072 #18 Feb 16 2025 08:32:47 %S A074072 0,1,3,105,13515,1771476585,3804217000364127435, %T A074072 140350834813144189858090274002849666665, %U A074072 23879457134773177491341539034414728352082211931046871698790017205810876429515 %N A074072 Numerators of iterations of Thue-Morse sequence. %H A074072 Amiram Eldar, <a href="/A074072/b074072.txt">Table of n, a(n) for n = 0..12</a> %H A074072 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Thue-MorseConstant.html">Thue-Morse Constant</a>. %e A074072 Fractions begin with 0, 1/4, 3/8, 105/256, 13515/32768, 1771476585/4294967296, ... %t A074072 f[0] = 0; f[n_] := (2^(-2^n))*(2^(2^(n - 1)) - 1)*(2^(2^(n - 1))*f[n - 1] + 1); Numerator@ Array[f, 9, 0] (* _Amiram Eldar_, Oct 05 2023 *) %Y A074072 Cf. A074073 (denominators). %K A074072 nonn,frac,easy %O A074072 0,3 %A A074072 _Eric W. Weisstein_, Aug 18 2002 %E A074072 a(8) from _Amiram Eldar_, Oct 05 2023