cp's OEIS Frontend

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.

A240123 Number of inequivalent ways to cut an n X n square into squares with integer sides, such that the dissection has a reflective symmetry in one diagonal, but no other symmetries.

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%I A240123 #13 Apr 05 2014 22:25:33
%S A240123 0,0,1,3,19,107,847,8647,119835,2255123,58125783,2050662011
%N A240123 Number of inequivalent ways to cut an n X n square into squares with integer sides, such that the dissection has a reflective symmetry in one diagonal, but no other symmetries.
%C A240123 'Inequivalent' has the same sense as in A224239: we do not regard dissections that differ by a rotation and/or reflection as distinct.
%H A240123 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 A240123 The three dissections for n=4:
%e A240123 ---------    ---------    ---------
%e A240123 |   | | |    |   |   |    |     | |
%e A240123 |   -----    |   |   |    |     ---
%e A240123 |   | | |    |   |   |    |     | |
%e A240123 ---------    ---------    |     ---
%e A240123 | | | | |    |   | | |    |     | |
%e A240123 ---------    |   -----    ---------
%e A240123 | | | | |    |   | | |    | | | | |
%e A240123 ---------    ---------    ---------
%Y A240123 Cf. A226980, A045846, A224239, A240124, A240125.
%K A240123 nonn,more
%O A240123 1,4
%A A240123 _Ed Wynn_, Apr 01 2014