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 A175531 Carmichael numbers of order 2. 3
 443372888629441, 39671149333495681, 842526563598720001, 2380296518909971201, 3188618003602886401 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Odd composite integer n is in this sequence if n == 1 or p (mod p^2 - 1) for every prime p|n. No other terms below 10^21. 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 Adjacent sequences: A175528 A175529 A175530 * A175532 A175533 A175534 KEYWORD nonn,hard,more AUTHOR Max Alekseyev, Jun 08 2010 STATUS approved

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Last modified November 26 17:13 EST 2022. Contains 358362 sequences. (Running on oeis4.)