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 A240108 Numbers with primitive root 20. 2
 3, 9, 13, 17, 23, 27, 37, 43, 47, 53, 67, 73, 81, 83, 103, 107, 113, 137, 157, 163, 167, 169, 173, 223, 227, 233, 243, 257, 263, 277, 283, 289, 293, 313, 317, 337, 347, 353, 367, 383, 397, 433, 443, 463, 467, 487, 503, 529, 547, 557, 563, 587, 593, 607 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..1000 MATHEMATICA pr = 20; Select[Range[2, 700], MultiplicativeOrder[pr, #] == EulerPhi[#] &] CROSSREFS Cf. numbers with positive primitive root r: A167791 (r=2), A167792 (r=3), A167793 (r=5), A167794 (r=6), A167795 (r=7), A167796 (r=8), A167797 (r=10), A240028 (r=11), A240030 (r=12), A240032 (r=13), A240094 (r=14), A240096 (r=15), A240100 (r=17), A240103 (r=18), A240106 (r=19). Cf. numbers with negative primitive root r: A167798 (r=-2), A167799 (r=-3), A167800 (r=-4), A167801 (r=-5), A167802 (r=-6), A167803 (r=-7), A167804 (r=-8), A167805 (r=-9), A167806 (r=-10), A240029 (r=-11), A240031 (r=-12), A240093 (r=-13), A240095 (r=-14), A240097 (r=-15), A240100 (r=-17), A240102 (r=-18), A240104 (r=-19), A240107 (r=-20). Sequence in context: A345460 A239320 A243656 * A163595 A088090 A075326 Adjacent sequences:  A240105 A240106 A240107 * A240109 A240110 A240111 KEYWORD nonn AUTHOR Vincenzo Librandi, Apr 01 2014 STATUS approved

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Last modified November 28 17:54 EST 2021. Contains 349415 sequences. (Running on oeis4.)