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A348462
Size of largest bipartite biregular Moore graph of diameter 6 and degrees n and 2.
2
12, 35, 78, 147, 248
OFFSET
2,1
COMMENTS
a(7) >= 387, a(8) = 570, a(9) = 803, a(10) = 1092.
LINKS
G. Araujo-Pardo, C. Dalfó, M. Á. Fiol and N. López, Bipartite biregular Moore graphs, arXiv:2103.11443 [math.CO], 2021.
G. Araujo-Pardo, C. Dalfó, M. Á. Fiol and N. López, Bipartite biregular Moore graphs, Discrete Math., 334 (2021), # 112582.
FORMULA
Empirical observation: For the terms a(2)-a(6) and a(8)-a(10) a(n) = A081437(n-1) + 2. It is unknown whether this is also valid for n = 7 and for n > 10. - Hugo Pfoertner, Oct 31 2021
a(n) <= A027620(n-2) + 3 = A081437(n-1) + 2 (the Moore bound). - Pontus von Brömssen, Oct 31 2021
CROSSREFS
KEYWORD
nonn,more
AUTHOR
N. J. A. Sloane, Oct 31 2021
STATUS
approved