A200323 For each composite m = A002808(n), a(n) is the smallest number k for which the equation x^m + (x+k)^m = (x+k+1)^m (mod m) has no solution, where x = 0..m-1.

2, 3, 2, 3, 3, 2, 2, 1, 2, 3, 2, 7, 2, 2, 1, 2, 3, 2, 3, 2, 1, 2, 1, 2, 3, 1, 2, 3, 2, 3, 4, 2, 2, 3, 2, 2, 3, 1, 2, 1, 3, 2, 2, 3, 2, 4, 3, 2, 1, 3, 2, 2, 1, 2, 2, 2, 2, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 3, 4, 1, 2, 2, 1, 2, 3, 2, 7, 3, 2, 3, 2, 2, 3, 1, 2, 1, 2

Offset

1,1

Links

Table of n, a(n) for n=1..87.

Example

a(12) = 7 because A002808(12) = 21 and the equation x^21 + (x+7)^21 = (x+8)^21 (mod 21)has no solution.

Maple

for n from 1 to 120 do: i:=0:for k from 1 to 500 while(i=0) do :ii:=0:for x from 0 to n-1 do:if x^n+(x+k)^n -(x+k+1)^n mod n =0 then ii:=ii+1:else fi:od: if ii=0 then i:=1:printf(`%d, `, k):else fi:od:od:

Crossrefs

Cf. A002808, A200046.

Sequence in context: A370455 A115397 A218656 * A075370 A332297 A030350

Adjacent sequences: A200320 A200321 A200322 * A200324 A200325 A200326

Keyword

nonn

Author

Michel Lagneau, Nov 16 2011

Status

approved