Geodesic
An exact bound on the number of proper $3$-edge-colorings of a connected cubic graph
Zapiski Nauchnykh Seminarov POMI, Combinatorics and graph theory. Part XII, Tome 497 (2020), pp. 26-52 
M. P. Ivanov. An exact bound on the number of proper $3$-edge-colorings of a connected cubic graph. Zapiski Nauchnykh Seminarov POMI, Combinatorics and graph theory. Part XII, Tome 497 (2020), pp. 26-52. http://geodesic.mathdoc.fr/item/ZNSL_2020_497_a1/
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     author = {M. P. Ivanov},
     title = {An exact bound on the number of proper $3$-edge-colorings of a connected cubic graph},
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     url = {http://geodesic.mathdoc.fr/item/ZNSL_2020_497_a1/}
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Voir la notice du chapitre de livre provenant de la source Math-Net.Ru

In this paper, the problem of finding an upper bound on the number of proper edge $3$-colorings of a connected cubic graph with $2n$ vertices is explored. For this purpose, we extended Karpov's method which allowed to obtain a weaker result earlier. The bounds $2^n+8$ for even $n$ and $2^n+4$ for odd $n$ was proved. We have found the unique series of graphs on which these bounds are attained. Thus for, in this problem the exact upper bound has been found and proved.

[1] D. V. Karpov, “O pravilnykh 3-raskraskakh reber kubicheskogo grafa”, Zap. nauchn. semin. POMI, 488, 2019, 31–48

[2] N. J. A. Sloane (redaktor), The On-Line Encyclopedia of Integer Sequences, https://oeis.org