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 A060262 a(n) is the smallest x such that p(x), p(x+1), ..., p(x+n-1) all have 10 as a primitive root, but p(x-1) and p(x+n) do not, where p(n)=A000040(n) is the n-th prime. 3
 4, 17, 55, 7, 93, 754, 2611, 31092, 55207, 301252, 955428, 805428 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS A prime p has 10 as a primitive root iff the length of the period of the decimal expansion of 1/p is p-1. LINKS MATHEMATICA test[p_] := MultiplicativeOrder[10, p]===p-1; For[n=1, n<100, n++, a[n]=0]; v=4; While[True, For[n=1, test[Prime[v+n]], n++, Null]; If[a[n]==0, a[n]=v; Print["a(", n, ") = ", v]]; For[v+=n+1, !test[Prime[v]], v++, Null]] CROSSREFS Cf. A001913, A002371, A060259, A060260, A060261. Sequence in context: A092091 A046995 A001585 * A157492 A108140 A213577 Adjacent sequences:  A060259 A060260 A060261 * A060263 A060264 A060265 KEYWORD nonn,more AUTHOR Jeff Burch, Mar 23 2001 EXTENSIONS Edited by Dean Hickerson, Jun 17 2002 STATUS approved

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Last modified May 15 20:00 EDT 2021. Contains 343920 sequences. (Running on oeis4.)