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 A242960 Numbers n such that 7^A000010(n) == 1 (mod n^2). 10
 4, 5, 10, 20, 40, 80, 491531, 983062, 1966124, 2457655, 3932248, 4915310, 6389903, 9339089, 9830620, 12288275, 12779806, 18678178, 19169709, 19661240, 24576550, 25559612, 28017267, 31949515, 37356356, 38339418, 39322480, 46695445, 49153100, 51119224, 56034534 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Giovanni Resta, Table of n, a(n) for n = 1..425 PROG (PARI) for(n=2, 10^9, if(Mod(7, n^2)^(eulerphi(n))==1, print1(n, ", "))) CROSSREFS Cf. A077816, A242959, A000010. All primes in this sequence are in A123693. Sequence in context: A185875 A049898 A166577 * A288141 A203853 A109675 Adjacent sequences:  A242957 A242958 A242959 * A242961 A242962 A242963 KEYWORD nonn AUTHOR Felix FrÃ¶hlich, May 27 2014 EXTENSIONS Terms a(23) and beyond from Giovanni Resta, Jan 24 2020 STATUS approved

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Last modified May 25 16:33 EDT 2020. Contains 334595 sequences. (Running on oeis4.)