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Discriminator of sequence A001566.
2

%I #16 May 14 2016 13:43:46

%S 1,3,3,7,37,37,37,37,37,37,59,59,59,59,73,73,73,73,73,97,97,97,137,

%T 157,157,157,157,157,157,157,157,157,157,157,157,157,157,157,157,157,

%U 251,251,251,251,251,251,251,251,251,251,277,277,277,277,277,277,277

%N Discriminator of sequence A001566.

%C The discriminator of a sequence is the least integer k such that the first n terms of the sequence are pairwise incongruent, modulo k.

%H Robert Israel, <a href="/A273043/b273043.txt">Table of n, a(n) for n = 1..10000</a>

%p N:= 1000: # to get a(1)..a(n)

%p nmax:= 0:

%p for m from 1 while nmax <= N do

%p a:= 3 mod m; A:= {a};

%p for n from 1 while nops(A) = n do

%p a:= a^2 - 2 mod m;

%p A:= A union {a};

%p od:

%p for k from nmax+1 to n-1 do v[k]:= m od:

%p nmax:= max(nmax,n-1);

%p od:

%p seq(v[k],k=1..N); # _Robert Israel_, May 13 2016

%Y Cf. A001566.

%K nonn

%O 1,2

%A _Jeffrey Shallit_, May 13 2016

%E a(13)-a(28) from _Tom Edgar_, May 13 2016

%E a(29)-a(57) from _Robert Israel_, May 13 2016