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A003570 a(n) = least positive number m such that 8^m == +1 or -1 mod 2n + 1, with a(0) = 0 by convention. 0
0, 1, 2, 1, 1, 5, 2, 4, 4, 3, 2, 11, 10, 3, 14, 5, 5, 4, 6, 4, 10, 7, 4, 23, 7, 8, 26, 20, 3, 29, 10, 2, 2, 11, 22, 35, 3, 20, 10, 13, 9, 41, 8, 28, 11, 4, 10, 12, 8, 5, 50, 17, 4, 53, 6, 12, 14, 44, 4, 8, 55, 20, 50, 7, 7, 65, 6, 12, 34, 23, 46, 20, 14, 14, 74, 5, 8, 20, 26, 52, 11, 27, 20, 83 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

COMMENTS

Multiplicative suborder of 8 (mod 2n+1) = sord(8, 2n+1). - Harry J. Smith (hjsmithh(AT)sbcglobal.net), Feb 11 2005

REFERENCES

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

LINKS

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

Eric Weisstein's World of Mathematics, Link to a section of The 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.

CROSSREFS

Sequence in context: A128704 A075259 A169589 * A011281 A100398 A160364

Adjacent sequences:  A003567 A003568 A003569 * A003571 A003572 A003573

KEYWORD

nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

More terms from Harry J. Smith (hjsmithh(AT)sbcglobal.net), Feb 11 2005

Edited by N. J. A. Sloane (njas(AT)research.att.com), May 22 2008 at the suggestion of Jeremy Gardiner

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Last modified February 14 23:53 EST 2012. Contains 205689 sequences.