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The number of switching equivalent classes of cube root edge weighted graphs.
0

%I #25 Sep 21 2024 08:42:26

%S 1,1,2,4,14,120,3222,271287,64154817,41653775052,74220906305025,

%T 364602274426789164

%N The number of switching equivalent classes of cube root edge weighted graphs.

%C a(n) is also the number of cube root two-graphs, up to isomorphism.

%H Y. Cheng and A. L. Wells, <a href="https://doi.org/10.1016/0095-8956(86)90075-4">Switching classes of directed graphs</a>, Journal of Combinatorial Theory, Series B, Vol. 40-2 (1986), p. 169-186.

%H Akihiro Higashitani and Kenta Ueyama, <a href="https://arxiv.org/abs/2409.10904">Combinatorics of graded module categories over skew polynomial algebras at roots of unity</a>, arXiv:2409.10904 [math.RA], 2024. See p. 11.

%H T. R. Hoffman and J. P. Solazzo, <a href="http://arxiv.org/abs/1408.0334">Complex two-graphs via equiangular tight frames</a>, arXiv preprint, arXiv:1408.0334 [math.CO], 2014-2017.

%K nonn,more

%O 1,3

%A _Thomas R. Hoffman_, Aug 05 2014

%E a(8)-a(12) added by _Andrew Howroyd_, Aug 31 2018

%E a(1)=a(2)=1 from Higashitani and Ueyama prepended by _Stefano Spezia_, Sep 21 2024