OFFSET
0,3
COMMENTS
Multiplicative suborder of 8 (mod 2n+1) = sord(8, 2n+1). - Harry J. Smith, Feb 11 2005
REFERENCES
H. Cohen, Course in Computational Algebraic Number Theory, Springer, 1993, p. 25, Algorithm 1.4.3
LINKS
Eric Weisstein's World of Mathematics, Multiplicative Order.
S. Wolfram, Algebraic Properties of Cellular Automata (1984), Appendix B.
EXAMPLE
a(1) = 1 since 8^1 = 8 == -1 (mod 3).
a(2) = 2 since 8^2 = 64 == -1 (mod 5).
MATHEMATICA
Suborder[k_, n_] := If[n > 1 && GCD[k, n] == 1, Min[MultiplicativeOrder[k, n, {-1, 1}]], 0];
a[n_] := Suborder[8, 2 n + 1];
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
More terms from Harry J. Smith, Feb 11 2005
Edited by N. J. A. Sloane, May 22 2008 at the suggestion of Jeremy Gardiner
STATUS
approved