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A175531 Carmichael numbers of order 2. 3
443372888629441, 39671149333495681, 842526563598720001, 2380296518909971201, 3188618003602886401, 4208895375600667752001 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Odd composite integer k is in this sequence if k == 1 or p (mod p^2 - 1) for every prime p|k.
LINKS
Everett W. Howe, Higher-order Carmichael numbers, Math. Comp. 69 (2000), 1711-1719. doi:10.1090/S0025-5718-00-01225-4
CROSSREFS
Subsequence of A002997, A175530, and A299799.
Sequence in context: A261150 A181392 A299799 * A186914 A172665 A172601
KEYWORD
nonn,hard,more
AUTHOR
Max Alekseyev, Jun 08 2010
EXTENSIONS
a(6) calculated using data from Claude Goutier and added by Amiram Eldar, Apr 20 2024
STATUS
approved

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Last modified June 18 14:16 EDT 2024. Contains 373481 sequences. (Running on oeis4.)