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 A072756 #5 Oct 24 2024 18:36:15 %S A072756 0,1,2,4,5,8,9,10,11,14,17,18,19,20,22,23,24,26,29,31,32,35,37,38,40, %T A072756 41,42,44,45,47,49,50,51,53,54,56,58,59,62,64,65,68,69,71,72,74,77,78, %U A072756 80,82,83,85,86,89,90,91,92,94,95,98,99,100,101,104,105,107,109,110 %N A072756 a(n) = least nonnegative integer not a(k) and not a(k)+floor(a(k)/2) for k<n. %Y A072756 Cf. A072757, A072758, A072759. %K A072756 nonn %O A072756 0,3 %A A072756 _Clark Kimberling_, Jul 09 2002