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A243089 Pseudoprimes to base 7 that are not squarefree. 5
25, 325, 1825, 4525, 4825, 10225, 12025, 16725, 20425, 30025, 35425, 58825, 177025, 216525, 265525, 352225, 526825, 611425, 675925, 710425, 717025, 746425, 772525, 784225, 834025, 877825, 1125825, 1126225, 1439425, 1491025, 1579225, 1935025, 1973425, 2176525 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Any term is divisible by the square of a base 7 Wieferich prime (A123693).

Intersection of A005938 and A013929. - Michel Marcus, Aug 21 2014

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..3095 (terms below 10^12)

PROG

(PARI) forcomposite(n=1, 1e9, if(Mod(7, n)^(n-1)==1, if(!issquarefree(n), print1(n, ", "))))

CROSSREFS

Cf. A005938, A123693, A158358, A243010, A243090, A244065.

Sequence in context: A000446 A124980 A188355 * A079875 A162702 A010977

Adjacent sequences:  A243086 A243087 A243088 * A243090 A243091 A243092

KEYWORD

nonn

AUTHOR

Felix Fröhlich, Aug 18 2014

STATUS

approved

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Last modified July 3 18:09 EDT 2022. Contains 355055 sequences. (Running on oeis4.)