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 A242860 a(n) is the least k >= 2 such that k is neither a square modulo n nor a primitive root (mod n), or 0 if no such value exists. 0
 0, 2, 0, 2, 6, 2, 3, 2, 10, 2, 5, 6, 2, 2, 0, 2, 8, 2, 2, 2, 22, 2, 5, 2, 3, 2, 12, 2, 6, 2, 2, 6, 2, 2, 6, 2, 2, 2, 3, 2, 2, 2, 2, 10, 46, 2, 6, 2, 2, 2, 23, 2, 2, 2, 2, 2, 58, 2, 8, 6, 2, 2, 2, 2, 3, 2, 2, 2, 14, 2, 7, 2, 2, 2, 2, 2, 12, 2, 3, 3, 82, 2, 2, 2 (list; graph; refs; listen; history; text; internal format)
 OFFSET 3,2 COMMENTS a(A019434(n)) = 0 for n >= 1. LINKS Table of n, a(n) for n=3..86. Eric Weisstein's World of Mathematics, Primitive Root PROG (Magma) lst:=[]; for n in [3..86] do v:=0; for r in [2..n-1] do if not IsSquare(ResidueClassRing(n)! r) and not IsPrimitive(r, n) then v:=r; break; end if; end for; lst:=Append(lst, v); end for; lst; CROSSREFS Cf. A028730, A136804, A136806. Sequence in context: A344873 A306079 A373167 * A320239 A033727 A033757 Adjacent sequences: A242857 A242858 A242859 * A242861 A242862 A242863 KEYWORD nonn AUTHOR Arkadiusz Wesolowski, May 24 2014 STATUS approved

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Last modified September 13 04:25 EDT 2024. Contains 375859 sequences. (Running on oeis4.)