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A218766 Composite numbers with both 10 and -10 as primitive root. 1
289, 841, 3721, 4913, 9409, 11881, 12769, 22201, 24389, 32761, 37249, 52441, 54289, 66049, 72361, 83521, 97969, 113569, 151321, 187489, 212521, 226981, 259081, 292681, 332929, 351649, 491401, 502681, 674041, 707281, 734449, 877969, 885481, 908209, 912673 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The powers of primes from A007349.

Intersection of A002808, A167797 and A167806.

LINKS

Arkadiusz Wesolowski, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Primitive Root

EXAMPLE

12769 = 113^2 belongs to this sequence because 113 is in A007349.

MATHEMATICA

lst = {}; r = 912673; Do[If[PrimeQ[i] && MultiplicativeOrder[10, i] == MultiplicativeOrder[-10, i] == i - 1, n = 2; While[(p = i^n) <= r, AppendTo[lst, p]; n++]], {i, Floor@Sqrt[r]}]; Sort[lst]

CROSSREFS

Cf. A007349.

Sequence in context: A156572 A157990 A261111 * A188186 A112077 A152934

Adjacent sequences:  A218763 A218764 A218765 * A218767 A218768 A218769

KEYWORD

nonn

AUTHOR

Arkadiusz Wesolowski, Nov 05 2012

STATUS

approved

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Last modified July 24 20:26 EDT 2021. Contains 346273 sequences. (Running on oeis4.)