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%I #12 Oct 22 2023 16:45:45
%S 1,4,10,5,10,7,3,2,3,9,11,8,4,14,55,7,34,14,8,11,26,29,6,16,11,15,5,
%T 20,29,4,41,8,26,4,35,68,15,10,26,53,23,7,44,44,57,20,14,20,65,100,34,
%U 23,40,12,14,112,38,20,35,6,27,35,50,3,130,253,89,6,13,40
%N Least number m such that 8^m == +- 1 (mod 8n + 1).
%t lnm[n_]:=Module[{m=1},While[PowerMod[8,m,8n+1]!=1&&PowerMod[ 8,m,8n+1] !=8n,m++];m]; Array[lnm,60] (* _Harvey P. Dale_, Jul 17 2016 *)
%K nonn
%O 1,2
%A _N. J. A. Sloane_