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A240666 Least k such that k^m == -1 (mod prime(n)) has a solution for some m. 1
3, 2, 2, 3, 2, 2, 2, 2, 5, 2, 3, 2, 2, 2, 5, 2, 2, 2, 2, 7, 3, 3, 2, 3, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 2, 3, 2, 2, 5, 2, 2, 2, 7, 2, 2, 3, 2, 3, 2, 2, 3, 7, 2, 2, 2, 5, 2, 3, 2, 2, 2, 2, 2, 11, 2, 2, 2, 3, 2, 2, 2, 7, 3, 2, 2, 5, 2, 2, 2, 2, 2, 2, 7, 2, 3, 2, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Looking at sequences A240657-A240665, one sees many 0 terms. This sequence finds the least k having a solution. Is the least k always prime?

LINKS

T. D. Noe, Table of n, a(n) for n = 1..10000

MATHEMATICA

Table[p = Prime[n]; k = 2; While[s = Select[Range[p/2], PowerMod[k, #, p] == p - 1 &, 1]; s == {}, k++]; k, {n, 100}]

CROSSREFS

Cf. A240657-A240665.

Sequence in context: A183049 A178086 A281977 * A052901 A127807 A122028

Adjacent sequences:  A240663 A240664 A240665 * A240667 A240668 A240669

KEYWORD

nonn

AUTHOR

T. D. Noe, Apr 15 2014

STATUS

approved

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Last modified October 16 13:51 EDT 2019. Contains 328093 sequences. (Running on oeis4.)