OFFSET
1,1
COMMENTS
This is the special case k=2 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}.
An infinite coprime sequence
LINKS
FORMULA
a(1)=3, a(2)=5, a(n)=-2+a(1)*a(2)*...*a(n-1) [typo corrected by Vincenzo Librandi, Feb 08 2010]
a(n)=a(n-1)^2+2*a(n-1)-2, for n>3.
Apparently a(n)=A003010(n-2)-1 for n>=3. - R. J. Mathar, Apr 22 2007
MAPLE
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(2, n), n=1..9);
MATHEMATICA
Join[{3, 5}, NestList[#^2+2#-2&, 13, 6]] (* Harvey P. Dale, Mar 05 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Seppo Mustonen, Sep 11 2005
STATUS
approved