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A153519 Nonprime numbers k such that 10^k == 10 (mod k) and are not Carmichael numbers. 3
1, 6, 9, 10, 15, 18, 30, 33, 45, 55, 90, 91, 99, 165, 246, 259, 370, 385, 451, 481, 495, 505, 657, 703, 715, 909, 1035, 1045, 1233, 1626, 2035, 2409, 2981, 3333, 3367, 3585, 4005, 4141, 4187, 4521, 4545, 5005, 5461, 6533, 6541, 6565, 7107, 7471, 7777, 8149 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Old name: Members of A121014 which are not Carmichael numbers A002997.
LINKS
MATHEMATICA
Select[Range[8000], !PrimeQ[#] && PowerMod[10, #, #] == Mod[10, #] && !(# > 1 && Divisible[# - 1, CarmichaelLambda[#]]) &] (* Amiram Eldar, Mar 19 2020 *)
PROG
(PARI) isok(n) = !isprime(n) && !is_A002997(n) && (Mod(10^n, n) == Mod(10, n)); \\ Michel Marcus, Nov 06 2013
CROSSREFS
Sequence in context: A359277 A054020 A121014 * A020219 A175634 A134622
KEYWORD
nonn
AUTHOR
Artur Jasinski, Dec 28 2008
EXTENSIONS
New name from Michel Marcus, Nov 06 2013
STATUS
approved

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Last modified May 25 13:47 EDT 2024. Contains 372788 sequences. (Running on oeis4.)