A240664 Least k such that 9^k == -1 (mod prime(n)), or 0 if no such k exists.
1, 0, 1, 0, 0, 0, 4, 0, 0, 7, 0, 0, 2, 0, 0, 13, 0, 0, 0, 0, 3, 0, 0, 22, 12, 25, 0, 0, 0, 28, 0, 0, 34, 0, 37, 0, 0, 0, 0, 43, 0, 0, 0, 4, 49, 0, 0, 0, 0, 0, 58, 0, 30, 0, 64, 0, 67, 0, 0, 70, 0, 73, 0, 0, 0, 79, 0, 42, 0, 0, 88, 0, 0, 0, 0, 0, 97, 0, 100, 51, 0
Offset: 1
Keywords
Links
- T. D. Noe, Table of n, a(n) for n = 1..1000
Crossrefs
Cf. A211245 (order of 9 mod prime(n)).
Programs
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Mathematica
Table[p = Prime[n]; s = Select[Range[p/2], PowerMod[9, #, p] == p - 1 &, 1]; If[s == {}, 0, s[[1]]], {n, 100}]
Comments