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%I #26 Nov 01 2021 00:45:44
%S 8,30,80,170,312
%N Size of largest bipartite biregular Moore graph of diameter 4 and degrees n and n.
%C a(7) >= 516, a(8) = 800, a(9) = 1170, a(10) = 1640.
%H G. Araujo-Pardo, C. Dalfó, M. Á. Fiol and N. López, <a href="https://arxiv.org/abs/2103.11443">Bipartite biregular Moore graphs</a>, arXiv:2103.11443 [math.CO], 2021.
%H G. Araujo-Pardo, C. Dalfó, M. Á. Fiol and N. López, <a href="https://doi.org/10.1016/j.disc.2021.112582">Bipartite biregular Moore graphs</a>, Discrete Math., 334 (2021), # 112582.
%F Empirical observation: For the terms a(2)-a(6) and a(8)-a(10) a(n) = 2*(A027444(n-1) + 1). It is unknown whether this is also valid for n = 7 and n > 10. - _Hugo Pfoertner_, Oct 31 2021
%F Is this the same as 2*A053698(n-1)? If not, where is the first place these sequences differ? - _Omar E. Pol_, Oct 31 2021
%F a(n) <= 2*A053698(n-1) (the Moore bound). - _Pontus von Brömssen_, Oct 31 2021
%Y Cf. A027444, A053698, A348462, A348463.
%K nonn,more
%O 2,1
%A _N. J. A. Sloane_, Oct 31 2021
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