This is a list of $s(n^2\!-\!n\!-\!1)$ packings (a pattern found by Joe DeVincentis in April 2014), shown alongside any packings that may beat them in optimality. For the main list, see Squares in Squares.
Where the word "alternative" is used, this designates an alternative packing, which is enclosed within the same-sized bounding square as another packing, but cannot be reached by continuously translating and/or rotating the squares in that packing. When the packing can be reached by such continuous transformations, the word "rearrangement" is used. For more information on each packing, view its SVG's source code.
For odd $n$, there is a predictable ordered $s(n^2\!-\!n\!-\!1)$ pattern that continues to infinity. For even $n$, the optimal packing tends to be chaotic and unorderly.
Zoom:
5.
$s = 2 + { 1\over 2}\sqrt 2 = \Nn{2.70710678118654}$
Rigid.
Proved by Frits Göbel
in early 1979.
29.
$s = \Nn{5.93434180499654}$
Found by Thierry Gensane
and Philippe Ryckelynck
in April 2004.
41.
$s = {}^{4}🔒 = \Nn{6.93786550630255}$
$s^4-16s^3+95s^2-218s-34=0$
Found by Joe DeVincentis
in April 2014.
89.
A continuation of the pattern may exist for $s(89)$, but is unlikely to be optimal.
$s = 5 + {7\over 2}\sqrt 2 = \Nn{9.94974746830583}$
Found by Evert Stenlund in 1980,
by extending a pattern found
by Frits Göbel in early 1979.
Likely beats the $s(n^2\!-\!n\!-\!1)$ pattern.
Explore group
131.
$s = \Nn{11.97614140898726}$
Found by Károly Hajba
in November 2024.
Doesn't beat an optimized
$s(n^2\!-\!n\!-\!1)$ pattern.
$s = \Nn{11.97350182495032}$
Found by David Ellsworth
in November 2024.
155.
$s = {}^{4}🔒 = \Nn{12.97970624703929}$
$s^4-28s^3+299s^2-1376s+332=0$
For more details, see Erich Friedman's paper on the subject: Packing Unit Squares in Squares: A Survey and New Results (or David Ellsworth's edit).