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 A221841 #16 Nov 29 2013 13:35:24 %S A221841 1,0,0,1,0,1,2,6,16,56,183,657,2277,8813,34178,137578,558734,2285694 %N A221841 Number of ways to dissect a square into n squares up to symmetry. %H A221841 Ed Wynn, <a href="http://arxiv.org/abs/1308.5420">Exhaustive generation of Mrs Perkins's quilt square dissections for low orders</a>, 2013, arXiv:1308.5420 %e A221841 For n = 7 there are a(7) = 2 ways: %e A221841 +---+---+ +---+---+ %e A221841 | | | | | | %e A221841 | | | | | | %e A221841 | | | | | | %e A221841 +-+-+-+-+ +---+-+-+ %e A221841 | | | | | | | | %e A221841 +-+ +-+ | +-+-+ %e A221841 | | | | | | | | %e A221841 +-+---+-+ +---+-+-+ %Y A221841 Cf. A221840, A221842. %K A221841 nonn,nice,more %O A221841 1,7 %A A221841 _Geoffrey H. Morley_, Jan 26 2013 %E A221841 a(10) corrected (thanks to _Ed Wynn_) by _Geoffrey H. Morley_, Aug 02 2013 %E A221841 More terms from Wynn, 2013. - _N. J. A. Sloane_, Nov 29 2013