The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A091733 a(n) is the least m > 1 such that m^3 = 1 (mod n). 2
 2, 3, 4, 5, 6, 7, 2, 9, 4, 11, 12, 13, 3, 9, 16, 17, 18, 7, 7, 21, 4, 23, 24, 25, 26, 3, 10, 9, 30, 31, 5, 33, 34, 35, 11, 13, 10, 7, 16, 41, 42, 25, 6, 45, 16, 47, 48, 49, 18, 51, 52, 9, 54, 19, 56, 9, 7, 59, 60, 61, 13, 5, 4, 65, 16, 67, 29, 69, 70, 11, 72, 25, 8, 47, 76, 45, 23, 55, 23 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(n) <= n + 1; the inequality is strict iff n is divisible by 9 or by a prime congruent to 1 mod 3. - Robert Israel, May 27 2014 LINKS Robert Israel, Table of n, a(n) for n = 1..10000 EXAMPLE a(7) = 2 because 2^3 is congruent to 1 (mod 7). MAPLE A:= n -> min(select(t -> type((t^3-1)/n, integer), [\$2 .. n+1])); map(A, [\$1 .. 1000]); # Robert Israel, May 27 2014 MATHEMATICA f[n_] := Block[{x = 2}, While[Mod[x^3 - 1, n] != 0, x++]; x]; Array[f, 79] (* Robert G. Wilson v, Mar 29 2016 *) PROG (MATLAB) m = 2; while mod(m^3 - 1, n); m = m + 1; end; m (PARI) a(n) = my(k = 2); while(Mod(k, n)^3 != 1, k++); k; \\ Michel Marcus, Mar 30 2016 CROSSREFS Cf. A070667, A076947, A083501. Sequence in context: A173527 A043267 A167514 * A066990 A097449 A104415 Adjacent sequences:  A091730 A091731 A091732 * A091734 A091735 A091736 KEYWORD easy,nonn AUTHOR David Wasserman, Mar 05 2004 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 18 15:25 EDT 2021. Contains 343995 sequences. (Running on oeis4.)