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%I #2 Mar 30 2012 18:59:35
%S 5,9,41,1841,3396641,11537183669441,133106607022462246291930241,
%T 17717368833032195779538884761310335951434822778039041
%N Integers with mutual residues -4.
%C This is the special case k=4 of sequences with mutual residues -k. In general, a(1)=k+1 and a(n)=min{m | m>a(n-1), mod(m,a(i))=-k, i=1,...,n-1}.
%C An infinite coprime sequence
%H S. Mustonen, <a href="http://www.survo.fi/papers/resseq.pdf">On integer sequences with mutual k-residues</a>
%F a(1)=5, a(2)=9, a(n)=-1+a(1)*a(2)*...*a(n-1)
%F a(n)=a(n)^2+4*a(n)-4, n>3
%p a:=proc(k,n::nonnegint) option remember; if n<3 then RETURN(n*k+1); fi; if n=3 then RETURN(a(k,1)*a(k,2)-k); fi; a(k,n-1)*(a(k,n-1)+k)-k; end; seq(a(4,n),n=1..9);
%K nonn
%O 1,1
%A _Seppo Mustonen_, Sep 11 2005
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