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A125775 Numbers n such that (5^n mod n) = (5^n mod n^2). 3
1, 2, 4, 5, 6, 12, 25, 42, 52, 84, 125, 156, 186, 372, 625, 1092, 1218, 1302, 1806, 2436, 2604, 2756, 3125, 3612, 4836, 5334, 7212, 8268, 10668, 12324, 15625, 15918, 18858, 19140, 20771, 24492, 26080, 31668, 31836, 33852, 37716, 37758, 40487, 41542 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Includes all powers of 5.

a(2) = 2, a(4) = 5, a(35) = 20771 and a(43) = 40487 are the only listed primes. More known primes are listed in A123692.

LINKS

Table of n, a(n) for n=1..44.

MATHEMATICA

Do[f=PowerMod[5, n, n]; g=PowerMod[5, n, n^2]; If[f==g, Print[n]], {n, 1, 1000000}]

CROSSREFS

Cf. A123692, A068535, A125773, A125774

Sequence in context: A182109 A006539 A031150 * A331624 A191165 A324778

Adjacent sequences:  A125772 A125773 A125774 * A125776 A125777 A125778

KEYWORD

nonn

AUTHOR

Alexander Adamchuk, Dec 07 2006

STATUS

approved

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Last modified August 9 04:39 EDT 2020. Contains 336319 sequences. (Running on oeis4.)