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 A184431 #4 Mar 30 2012 18:57:13 %S A184431 1,3,4,5,7,8,9,10,11,13,14,15,16,17,18,19,21,22,23,24,25,26,27,28,29, %T A184431 30,31,32,33,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,51,52,53,54, %U A184431 55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,102,103,104,105,106,107,108 %N A184431 Lower s-Wythoff sequence, where s=A184431 (eighth-cubes). Complement of A184432. %C A184431 See A184117 for the definition of lower and upper s-Wythoff sequences. %t A184431 mex:=First[Complement[Range[1,Max[#1]+1],#1]]&; %t A184431 s[n_]:=Floor[((n+1)/2)^3];a[1]=1;b[n_]:=b[n]=s[n]+a[n]; %t A184431 a[n_]:=a[n]=mex[Flatten[Table[{a[i],b[i]},{i,1,n-1}]]]; %t A184431 Table[s[n],{n,40}] %t A184431 Table[a[n],{n,100}] %t A184431 Table[b[n],{n,100}] %Y A184431 Cf. A184117, A184432. %K A184431 nonn %O A184431 1,2 %A A184431 _Clark Kimberling_, Jan 14 2011