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A206904 n+[nr/s]+[nt/s], where []=floor, r=3, s=sqrt(3), t=1/s.

%I A206904 #9 Mar 30 2012 18:58:12
%S A206904 2,5,9,11,14,18,21,23,27,30,33,36,39,42,45,48,51,55,57,60,64,67,69,73,
%T A206904 76,79,82,85,88,91,94,97,101,103,106,110,113,115,119,122,125,128,131,
%U A206904 134,137,140,143,147,149,152,156,159,161,165,168,170,174,177
%N A206904 n+[nr/s]+[nt/s], where []=floor, r=3, s=sqrt(3), t=1/s.
%C A206904 The sequences A206903, A206904, A206905 partition the positive integers.  To generate them, jointly rank the sets {n/3}, {n/sqrt(3)}, {n*sqrt(3)} for n>=1.  The positions of n/3 in the joint ranking form A206903, and likewise for the other sequences.
%t A206904 r = 3; s = Sqrt[3]; t = 1/s;
%t A206904 a[n_] := n + Floor[n*s/r] + Floor[n*t/r];
%t A206904 b[n_] := n + Floor[n*r/s] + Floor[n*t/s];
%t A206904 c[n_] := n + Floor[n*r/t] + Floor[n*s/t];
%t A206904 Table[a[n], {n, 1, 70}]  (* A206903 *)
%t A206904 Table[b[n], {n, 1, 70}]  (* A206904 *)
%t A206904 Table[c[n], {n, 1, 70}]  (* A206905 *)
%Y A206904 Cf. A206903, A206905.
%K A206904 nonn
%O A206904 1,1
%A A206904 _Clark Kimberling_, Feb 13 2012