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 A220165 #24 Jul 28 2024 17:00:01 %S A220165 0,0,0,0,0,0,0,0,1,0,0,9,33,104,280,948,3014,9494,30302,98897,323372, %T A220165 1080168,3666666,12604812,43734613,153788715 %N A220165 Number of nonsquare simple imperfect squared rectangles of order n up to symmetry. %C A220165 A squared rectangle is a rectangle dissected into a finite number, two or more, of squares. If no two of these squares have the same size the squared rectangle is perfect. A squared rectangle is simple if it does not contain a smaller squared rectangle. The order of a squared rectangle is the number of constituent squares. %D A220165 See A002881 and A006983. %H A220165 Stuart E. Anderson, <a href="http://www.squaring.net/sq/sr/sisr/sisr.html">Simple Imperfect Squared Rectangles, orders 9 to 24</a> %Y A220165 Cf. A002881, A006983, A002962, A002839. %K A220165 nonn,hard %O A220165 1,12 %A A220165 _Stuart E Anderson_, Dec 06 2012 %E A220165 a(25) from _Stuart E Anderson_, May 07 2024 %E A220165 a(26) from _Stuart E Anderson_, Jul 28 2024