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a(1) = 1; for n>1, a(n) = n*a(n-1) if GCD(n,a(n-1)) = 1 else a(n) = a(n-1).
1

%I #14 Sep 16 2021 10:48:54

%S 1,2,6,6,30,30,210,210,210,210,2310,2310,30030,30030,30030,30030,

%T 510510,510510,9699690,9699690,9699690,9699690,223092870,223092870,

%U 223092870,223092870,223092870,223092870,6469693230,6469693230,200560490130,200560490130

%N a(1) = 1; for n>1, a(n) = n*a(n-1) if GCD(n,a(n-1)) = 1 else a(n) = a(n-1).

%p a:=[1];

%p L:=1;

%p for n from 2 to 50 do

%p if igcd(n,L)=1 then L:=n*L; fi;

%p a:=[op(a),L];

%p od:

%p a; # - _N. J. A. Sloane_, Sep 15 2021

%t nxt[{n_,a_}]:={n+1,If[GCD[n+1,a]==1,a(n+1),a]}; NestList[nxt,{1,1},40][[All,2]] (* _Harvey P. Dale_, Sep 16 2021 *)

%K nonn

%O 1,2

%A _Amarnath Murthy_ and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jun 19 2003

%E Corrected and extended by _Harvey P. Dale_, Sep 16 2021