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 A206907 #8 Mar 30 2012 18:58:12 %S A206907 1,2,4,5,6,9,10,11,13,14,16,18,19,20,22,24,25,27,28,29,32,33,34,36,37, %T A206907 39,41,42,43,45,46,48,50,51,52,54,56,57,59,60,61,64,65,66,68,69,71,73, %U A206907 74,75,77,79,80,82,83,84,86,88,89,91,92,93,96,97,98,100,101 %N A206907 n+[nr/s]+[nt/s], where []=floor, r=1/3, s=sqrt(3), t=1/s. %C A206907 The sequences A206906, A206907, A206908 partition the positive integers. To generate them, jointly rank the sets {3n}, {n/sqrt(3)}, {n*sqrt(3)} for n>=1. The positions of 3n in the joint ranking form A206906, and likewise for the other sequences. %t A206907 r = 1/3; s = Sqrt[3]; t = 1/s; %t A206907 a[n_] := n + Floor[n*s/r] + Floor[n*t/r]; %t A206907 b[n_] := n + Floor[n*r/s] + Floor[n*t/s]; %t A206907 c[n_] := n + Floor[n*r/t] + Floor[n*s/t]; %t A206907 Table[a[n], {n, 1, 70}] (* A206906 *) %t A206907 Table[b[n], {n, 1, 80}] (* A206907 *) %t A206907 Table[c[n], {n, 1, 70}] (* A206908 *) %Y A206907 Cf. A206903. %K A206907 nonn %O A206907 1,2 %A A206907 _Clark Kimberling_, Feb 13 2012