%I #8 Jan 24 2019 02:02:33
%S 1,2,1,3,2,1,3,4,2,1,3,5,4,2,1,3,5,6,4,2,1,3,5,7,6,4,2,1,3,5,7,6,8,4,
%T 2,1,3,5,7,9,6,8,4,2,1,3,5,7,9,6,10,8,4,2,1,3,5,7,9,11,6,10,8,4,2,1,3,
%U 5,7,9,11,6,10,12,8,4,2,1,3,5,7,9,11,13,6,10,12,8,4,2,1
%N Triangular array: row n is the list of numbers from 1 to n, sorted in Sharkovsky order.
%H Luc Rousseau, <a href="/A323607/a323607.png">Array plot of the first 250 rows of the triangle</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/SharkovskysTheorem.html">Sharkovsky's Theorem</a>
%e Array begins:
%e 1
%e 2 1
%e 3 2 1
%e 3 4 2 1
%e 3 5 4 2 1
%e 3 5 6 4 2 1
%e 3 5 7 6 4 2 1
%e 3 5 7 6 8 4 2 1
%e 3 5 7 9 6 8 4 2 1
%e 3 5 7 9 6 10 8 4 2 1
%e 3 5 7 9 11 6 10 8 4 2 1
%e 3 5 7 9 11 6 10 12 8 4 2 1
%t lt[x_, y_] := Module[
%t {c, d, xx, yy, u, v},
%t {c, d} = IntegerExponent[#, 2] & /@ {x, y};
%t xx = x/2^c;
%t yy = y/2^d;
%t u = If[xx == 1, \[Infinity], c];
%t v = If[yy == 1, \[Infinity], d];
%t If[u != v, u < v, If[u == \[Infinity], c > d, xx < yy]]]
%t row[n_] := Sort[Range[n], lt]
%t row /@ Range[13] // Flatten
%Y Cf. A323608.
%K nonn,tabl
%O 1,2
%A _Luc Rousseau_, Jan 19 2019