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Let rep(n) be the n-th repunit number; sequence gives values of n such that rep(n) == rep(6) (mod n).
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%I #6 Mar 30 2012 18:38:52

%S 1,2,3,4,5,6,8,10,12,15,16,20,22,24,25,30,32,40,41,42,44,48,50,60,64,

%T 66,75,78,80,84,88,96,100,102,110,111,114,120,125,132,138,150,156,160,

%U 168,174,176,186,192,200,202,210,220,222,240,246,250,258,264,271,282

%N Let rep(n) be the n-th repunit number; sequence gives values of n such that rep(n) == rep(6) (mod n).

%Y Cf. A002275.

%K easy,nonn

%O 1,2

%A _Benoit Cloitre_, Mar 05 2002