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 A086743 #8 Jan 06 2021 22:50:42
%S A086743 1,2,4,5,6,7,8,10,11,13,14,15,16,17,18,19,20,21,22,23,24,25,26,28,29,
%T A086743 31,32,33,34,35,37,38,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,
%U A086743 56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79
%N A086743 Numbers n such that the coefficient of x^n equals 0 in Product_{k>=1} (1 - x^(3^k)).
%Y A086743 Cf. A074940, A083096.
%K A086743 nonn
%O A086743 1,2
%A A086743 _Benoit Cloitre_, Jul 29 2003