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%I #22 Apr 04 2024 10:52:26
%S 0,1,1,1,1,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,
%T 4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,
%U 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
%N Minimum diameter of a Cayley graph on the cyclic group Z_n with two generators.
%C Every diameter k>0 occurs 4*k times.
%C See A370461 for the directed case.
%H R. Beivide, E. Herrada, J. L. Balcazar, and A. Arruabarrena, <a href="https://doi.org/10.1109/12.93744">Optimal distance networks of low degree for parallel computers</a>, IEEE Trans. Comput. 40 (1991), no. 10, 1109-1124.
%F a(n) = ceiling((sqrt(2*n-1)-1)/2).
%e For n=26..41 the Cayley graph Cay(n;4,5) (circulant) has diameter a(n)=4.
%Y Cf. A370461.
%K nonn
%O 1,6
%A _Miquel A. Fiol_, Mar 19 2024