

A226746


Numbers n such that x^2 = 1 has more than two solutions in the Gaussian integers modulo n.


2



4, 5, 6, 8, 10, 12, 13, 14, 15, 16, 17, 18, 20, 21, 22, 24, 25, 26, 28, 29, 30, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 44, 45, 46, 48, 50, 51, 52, 53, 54, 55, 56, 57, 58, 60, 61, 62, 63, 64, 65, 66, 68, 69, 70, 72, 73, 74, 75, 76, 77, 78, 80, 82, 84, 85
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OFFSET

1,1


LINKS



EXAMPLE

13 is in the sequence because 5i, 8i, 1 and 12 are solutions of x^2 = 1 (mod 13).


MATHEMATICA

h[n_] := Flatten[Table[a + b I, {a, 0, n  1}, {b, 0, n  1}]]; sol[n_] := Select[h[n], Mod[#^2, n] == 1 &]; Select[Range[100], Length[sol[#]] > 2 &]


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



