Dominoes in Octagons

The following pictures show n dominoes (with short side 1) packed inside the smallest known octagon (with side s).

1.
           2.
           3.
s = 3–3/√2 = 0.87867+
Trivial.
  		s = √(4–2√2) = 1.08239+
Trivial.
  		s = √(5–√2–√(8√2–9)) = 1.43690+
Found by Maurizio Morandi
in May 2026.

4.
           5.
           6.
s = 1.57337+
Found by Maurizio Morandi
in May 2026. 		s = 1.71644+
Found by Jonathan Viquerat
in June 2026. 		s = √(6–√2–√(20√2–26)) = 1.75339+
Found by Maurizio Morandi
in May 2026.

7.
           8.
           9.
s = 2.00516+
Found by Jonathan Viquerat
in June 2026. 		s = 5(√2–1) = 2.07106+
Trivial.
  		s = 2.19803+
Found by Jonathan Viquerat
in June 2026.

10.
           11.
           12.
s = 2.32394+
Found by Jonathan Viquerat
in June 2026. 		s = 2.44911+
Found by Jonathan Viquerat
in June 2026. 		s = 6(√2–1) = 2.48528+
Trivial.
 

13.
           14.
           15.
s = 2.56556+
Found by Jonathan Viquerat
in June 2026. 		s = 2.67740+
Found by Jonathan Viquerat
in June 2026. 		s = 2.80446+
Found by Jonathan Viquerat
in June 2026.

16.
           17.
           18.
s = 2√(5–√2–√(8√2–9)) = 2.87381+
Found by Maurizio Morandi
in June 2026. 		s = 2.92285+
Found by Aapo Lipponen
in July 2026. 		s = 3.01566+
Found by Aapo Lipponen
in July 2026.

19.
           20.
s = 3.08791+
Found by Jonathan Viquerat
in June 2026. 		s = 3.16881+
Found by Jonathan Viquerat
in June 2026.