Triangles in Triangles

The following pictures show n equilateral triangles with side 1 packed inside the smallest known equilateral triangles (of side length s ). Most of these have not been proven.
1.            2.            3.
s = 1
Trivial. 		s = 2
Trivial. 		s = 2
Trivial.

4.            5.            6.
s = 2
Trivial. 		s = 1 + √3 = 2.732+
Proved by Erich Friedman in 1997. 		s = 2.980+
Found by Erich Friedman in 1997.

7.            8.            9.
s = 3
Found by Erich Friedman in 1997. 		s = 3
Found by Erich Friedman in 1997. 		s = 3
Trivial.

10.            11.            12.
s = 3.5
Found by Erich Friedman in 1997. 		s = 3.700+
Found by Erich Friedman in 1997. 		s = 2 + 2cos(π/9) = 3.879+
Found by David Cantrell in July 2007.

18.            19.            20.
s = 4.5
Found by Erich Friedman in 1997. 		s = 4.762+
Found by David Cantrell in July 2007. 		s = 9/2 + 1/√6 = 4.908+
Found by David Cantrell in July 2007.

26.            28.            29.
s = 5.488+
Found by David Cantrell in July 2007. 		s = 5.5
Found by Erich Friedman in 1997. 		s = 17/3 = 5.666+
Found by David Cantrell in July 2007.

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