0,6

a(n) is minimum e for which 7^e = +/-1 mod n, or zero if no e exists.

H. Cohen, Course in Computational Algebraic Number Theory, Springer, 1993, p. 25, Algorithm 1.4.3

Table of n, a(n) for n=0..90.

H. J. Smith, XICalc - Extra Precision Integer Calculator.

Eric Weisstein's World of Mathematics, Multiplicative Order.

S. Wolfram, Algebraic Properties of Cellular Automata (1984), Appendix B.

Sequence in context: A195017 A078806 A173438 * A121480 A082601 A286509

Adjacent sequences: A103490 A103491 A103492 * A103494 A103495 A103496

easy,nonn

Harry J. Smith, Feb 08 2005

approved