A103495 - OEIS

A103495

Multiplicative suborder of 9 (mod n) = sord(9, n).

0, 0, 1, 0, 1, 1, 0, 3, 1, 0, 1, 5, 0, 3, 3, 0, 2, 4, 0, 9, 2, 0, 5, 11, 0, 5, 3, 0, 3, 7, 0, 15, 4, 0, 4, 6, 0, 9, 9, 0, 2, 2, 0, 21, 5, 0, 11, 23, 0, 21, 5, 0, 3, 13, 0, 10, 3, 0, 7, 29, 0, 5, 15, 0, 8, 6, 0, 11, 8, 0, 6, 35, 0, 3, 9, 0, 9, 15, 0, 39, 2, 0, 2, 41, 0, 8, 21, 0, 5, 22, 0, 3, 11, 0, 23

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OFFSET

0,8

COMMENTS

a(n) is minimum e for which 9^e = +/-1 mod n, or zero if no e exists.

REFERENCES

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

LINKS

Table of n, a(n) for n=0..94.

Eric Weisstein's World of Mathematics, Multiplicative Order.

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

MATHEMATICA