%I #7 Oct 07 2018 07:57:42
%S 19,31,37,43,79,199,211,223,229,277,283,367,439,463,499,523,547,619,
%T 643,692,829,859,877,907,967,997
%N Primes p such that L(p^2) = (p-1)*L(p)/6, where L(i) = A279186(i).
%H Haifeng Xu, <a href="http://arxiv.org/abs/1601.06509">The largest cycles consist by the quadratic residues and Fermat primes</a>, arXiv:1601.06509 [math.NT], 2016.
%t T[n_, k_] := Module[{g, y, r}, If[k == 0, Return[1]]; y = n; g = GCD[k, y]; While[g > 1, y = y/g; g = GCD[k, y]]; If[y == 1, Return[1]]; r = MultiplicativeOrder[k, y]; r = r/2^IntegerExponent[r, 2]; If[r == 1, Return[1]]; MultiplicativeOrder[2, r]];
%t L[n_] := L[n] = Table[T[n, k], {k, 0, n - 1}] // Max;
%t For[p = 2, p < 1000, p = NextPrime[p], If[L[p^2] == (p-1) L[p]/6, Print[p]]] (* _Jean-François Alcover_, Oct 07 2018, after _Robert Israel_ in A279186 *)
%Y Cf. A279185-A279191.
%K nonn,more
%O 1,1
%A _N. J. A. Sloane_, Dec 14 2016
%E More terms from _Jean-François Alcover_, Oct 07 2018
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