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A122385 Smallest m such that (n^2 mod m) = (m^2 mod n). 4
1, 2, 2, 2, 4, 5, 5, 3, 3, 8, 9, 6, 10, 11, 4, 4, 14, 6, 16, 10, 8, 18, 19, 5, 5, 22, 9, 12, 11, 8, 26, 6, 6, 29, 6, 6, 14, 33, 26, 20, 36, 16, 37, 22, 12, 40, 41, 7, 7, 10, 45, 26, 47, 18, 21, 15, 38, 22, 52, 27, 54, 55, 8, 8, 58, 59, 60, 34, 39, 12, 19, 12, 65, 66, 15, 29, 69, 70, 71 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A122388(n) = n^2 mod a(n) = a(n)^2 mod n;

A122386(n) = a(a(n));

a(A122387(n)) = n, a(m) <> n for m < A122387(n).

LINKS

Table of n, a(n) for n=1..79.

EXAMPLE

10^2 mod 1 = 0 <> 1^2 mod 10 = 1,

10^2 mod 2 = 0 <> 2^2 mod 10 = 4,

10^2 mod 3 = 1 <> 3^2 mod 10 = 9,

10^2 mod 4 = 0 <> 4^2 mod 10 = 6,

10^2 mod 5 = 0 <> 5^2 mod 10 = 5,

10^2 mod 6 = 4 <> 6^2 mod 10 = 6,

10^2 mod 7 = 2 <> 7^2 mod 10 = 9,

10^2 mod 8 = 4 = 8^2 mod 10, therefore a(10) = 8.

CROSSREFS

Sequence in context: A240327 A308771 A007495 * A035002 A032578 A035659

Adjacent sequences:  A122382 A122383 A122384 * A122386 A122387 A122388

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Sep 01 2006

STATUS

approved

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Last modified December 3 05:05 EST 2021. Contains 349445 sequences. (Running on oeis4.)