Octagons in Octagons

The following pictures show n unit octagons packed inside the smallest known octagon (with side s).


1.
           2.
           3.
s = 1
Trivial.
 
s = 2
Trivial.
 
s = 5–2√2 = 2.17157+
Found by Ignacio Vallejo
in March 2026.


4.
           5.
           6.
s = √(5+1/√2) = 2.38895+
Found by Ignacio Vallejo
in March 2026.
s = 2+1/√2 = 2.70710+
Found by Ignacio Vallejo
in March 2026.
s = 2.98915+
Found by Ignacio Vallejo
in March 2026.


7.
           8.
           9.
s = 3
Trivial.
 
s = 3.27526+
Found by Ignacio Vallejo
in March 2026.
s = 2+√2 = 3.41421+
Found by Ignacio Vallejo
in March 2026.


10.
           11.
           12.
s = 3+1/√2 = 3.70710+
Found by Ignacio Vallejo
in March 2026.
s = 3.93270+
Found by Ignacio Vallejo
in March 2026.
s = 4
Trivial.
 


13.
           14.
           15.
s = 7–2√2 = 4.17157+
Found by Ignacio Vallejo
in March 2026.
s = 4.28155+
Found by Ignacio Vallejo
in March 2026.
s = 4.45594+
Found by Ignacio Vallejo
in March 2026.


16.
           17.
           18.
s = 4.59824+
Found by Ignacio Vallejo
in March 2026.
s = 4.75741+
Found by Ignacio Vallejo
in March 2026.
s = 4.85717+
Found by Ignacio Vallejo
in March 2026.


19.
           20.
           21.
s = 4.93586+
Found by Ignacio Vallejo
in March 2026.
s = 5.06781+
Found by Ignacio Vallejo
in March 2026.
s = 5.19715+
Found by Ignacio Vallejo
in March 2026.


22.
           23.
           24.
s = 5.35750+
Found by Ignacio Vallejo
in March 2026.
s = 5.41440+
Found by Ignacio Vallejo
in March 2026.
s = 5.55464+
Found by Ignacio Vallejo
in March 2026.


25.
           26.
           27.
s = 5.65593+
Found by Ignacio Vallejo
in March 2026.
s = 5.73940+
Found by Ignacio Vallejo
in March 2026.
s = 5.81238+
Found by Ignacio Vallejo
in March 2026.


28.
           29.
           30.
s = 5.82845+
Found by Ignacio Vallejo
in March 2026.
s = 6.05746+
Found by Ignacio Vallejo
in March 2026.
s = 6.15432+
Found by Ignacio Vallejo
in March 2026.