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A143663
a(n) is the least prime such that the multiplicative order of 3 mod a(n) equals n, or a(n)=1 if no such prime exists.
6
2, 1, 13, 5, 11, 7, 1093, 41, 757, 61, 23, 73, 797161, 547, 4561, 17, 1871, 19, 1597, 1181, 368089, 67, 47, 6481, 8951, 398581, 109, 29, 59, 31, 683, 21523361, 2413941289, 103, 71, 530713, 13097927, 2851, 313, 42521761, 83, 43, 431, 5501, 181, 23535794707
OFFSET
1,1
COMMENTS
If a(n) differs from 1, then a(n) is the minimal prime divisor of A064079(n).
LINKS
Max Alekseyev, Table of n, a(n) for n = 1..730 (first 153 terms from Robert G. Wilson v)
MAPLE
a:= proc(n) local f, p;
f:= numtheory:-factorset(3^n - 1);
for p in f do
if numtheory:-order(3, p) = n then return p fi
od:
1
end proc:
seq(a(n), n=1..100); # Robert Israel, Oct 13 2014
MATHEMATICA
p = 2; t = Table[0, {100}]; While[p < 100000001, a = MultiplicativeOrder[3, p]; If[0 < a < 101 && t[[a]] == 0, t[[a]] = p; Print[{a, p}]]; p = NextPrime@ p]; t (* Robert G. Wilson v, Oct 13 2014 *)
KEYWORD
nonn
AUTHOR
Vladimir Shevelev, Aug 28 2008
EXTENSIONS
More terms from Robert G. Wilson v, Dec 11 2013
STATUS
approved