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A279192 Primes p such that L(p^2) = (p-1)*L(p)/6, where L(i) = A279186(i). 2
19, 31, 37, 43, 79, 199, 211, 223, 229, 277, 283, 367, 439, 463, 499, 523, 547, 619, 643, 692, 829, 859, 877, 907, 967, 997 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..26.

Haifeng Xu, The largest cycles consist by the quadratic residues and Fermat primes, arXiv:1601.06509 [math.NT], 2016.

MATHEMATICA

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]];

L[n_] := L[n] = Table[T[n, k], {k, 0, n - 1}] // Max;

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 *)

CROSSREFS

Cf. A279185-A279191.

Sequence in context: A125148 A214798 A040066 * A159043 A040088 A178251

Adjacent sequences:  A279189 A279190 A279191 * A279193 A279194 A279195

KEYWORD

nonn,more

AUTHOR

N. J. A. Sloane, Dec 14 2016

EXTENSIONS

More terms from Jean-François Alcover, Oct 07 2018

STATUS

approved

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Last modified October 17 16:51 EDT 2019. Contains 328120 sequences. (Running on oeis4.)