This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A348133 #26 Oct 11 2021 18:33:55 %S A348133 3,4,5,5,6,7,7 %N A348133 Minimal number of horizontal and vertical lines needed to partition a square into rectangles which can be reassembled into n distinct squares. %C A348133 For n > 2 the values may only be upper bounds. %H A348133 Anonymous, <a href="https://bbs.emath.ac.cn/thread-18080-1-1.html">Divide a square into several small squares.</a> [A Chinese web site where the problem originated] %F A348133 a(n) <= a(n-2) + 2. %F A348133 a(k + m - 1) <= a(k) + a(m). %e A348133 For example, we could use one horizontal line to cut one side of the square in the ratio 2:3 and then two vertical lines to cut another side in the ratio 1:1:3 to form 6 rectangles 1*3, 1*3, 3*3, 1*2, 1*2, 3*2. Then we can reassemble the rectangles into a 3*3 square and a 4*4 square. So a(2) = 3. %K A348133 nonn,hard,more %O A348133 2,1 %A A348133 _Zhao Hui Du_, Oct 01 2021 %E A348133 Thanks to _Jinyuan Wang_ for additional comments.