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 A072190 Indices of primes with primitive root 2. 2
 2, 3, 5, 6, 8, 10, 12, 16, 17, 18, 19, 23, 26, 28, 32, 34, 35, 38, 40, 41, 42, 45, 47, 49, 57, 62, 66, 69, 70, 74, 75, 77, 81, 82, 86, 89, 91, 94, 97, 99, 100, 101, 102, 103, 107, 112, 114, 119, 120, 121, 123, 126, 127, 134, 137, 138, 139, 142, 144, 145, 147 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Artin conjectured that this sequence is infinite (this is the famous Artin Conjecture). REFERENCES M. Abramowitz and I.A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 864 J. H. Conway and R. K. Guy, The Book of Numbers, Copernicus Press, New York, 1996. see p. 169 L. Huber, manuscripts on Group Theory and Number Theory, 1990-1995 LINKS T. D. Noe, Table of n, a(n) for n = 1..1000 M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy]. EXAMPLE 8 is an element of the sequence: 19 the 8th prime and 2 is primitive root of 19. 9 is not element of the sequence, since 23 is the 9th prime and 2 is not primitive root of 23. MATHEMATICA Select[Range[300], MultiplicativeOrder[2, Prime[#]] == Prime[#] - 1 &] (* T. D. Noe, Apr 16 2014 *) CROSSREFS Cf. A001122, A001123, A001124, A001125. Sequence in context: A249013 A211964 A140199 * A177445 A022826 A053035 Adjacent sequences:  A072187 A072188 A072189 * A072191 A072192 A072193 KEYWORD easy,nonn AUTHOR Miklos Kristof, Jul 02 2002 EXTENSIONS Edited by N. J. A. Sloane, Apr 11 2009 Extended by T. D. Noe, Apr 16 2014 STATUS approved

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Last modified November 26 21:07 EST 2021. Contains 349344 sequences. (Running on oeis4.)