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 A221845 #20 Sep 05 2021 21:59:14 %S A221845 1,1,5,38,471,10661,450923,35863932,5353011030,1500957421749, %T A221845 790347882174803,781621363452395224,1451740730942350766747, %U A221845 5064070747064013555843107,33176273260130056822126522407 %N A221845 Number of prime dissections of an n X n square into integer-sided squares. %C A221845 A dissection into squares was called prime by _J. H. Conway_ in 1964 if the GCD of the sides of the squares is 1. %D A221845 J. H. Conway, Mrs Perkins's quilt, Proc. Camb. Phil. Soc., 60 (1964), 363-368. %H A221845 Ed Wynn, <a href="http://arxiv.org/abs/1308.5420">Exhaustive generation of Mrs Perkins's quilt square dissections for low orders</a>, arXiv:1308.5420 %e A221845 For n = 3 the a(3) = 5 dissections are: %e A221845 +-+-+-+ +-+-+-+ +-+-+-+ +-+---+ +---+-+ %e A221845 | | | | | | | | | | | | | | | | | | %e A221845 +-+-+-+ +-+-+-+ +-+-+-+ +-+ | | +-+ %e A221845 | | | | | | | | | | | | | | | | %e A221845 +-+-+-+ +-+ | | +-+ +-+-+-+ +-+-+-+ %e A221845 | | | | | | | | | | | | | | | | | | %e A221845 +-+-+-+ +-+---+ +---+-+ +-+-+-+ +-+-+-+ %Y A221845 Cf. A045846, A221844. %K A221845 nonn %O A221845 1,3 %A A221845 _Geoffrey H. Morley_, Jan 26 2013 %E A221845 Corrected and extended to a(15) by _Geoffrey H. Morley_, Feb 05 2013