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A273339
Smallest composite c such that n^(c-1) =/= 1 (mod c^2), i.e., smallest composite c that is not a "Wieferich pseudoprime" to base n.
3
4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 6, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 6, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 6, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 6, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 6, 4, 4, 4, 4, 4, 4, 4
OFFSET
2,1
COMMENTS
Smallest composite c such that n does not occur in row c of the array in A244752. - Felix Fröhlich, Jan 07 2017
LINKS
PROG
(PARI) a(n) = forcomposite(c=1, , if(Mod(n, c^2)^(c-1)!=1, return(c)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Felix Fröhlich, May 20 2016
STATUS
approved