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%I #28 Oct 24 2023 20:37:35
%S 3,12,156,24492,599882556,359859081592975692,
%T 129498558604939936868397356895854556,
%U 16769876680757063368089314196389622249367851612542961252860614401811692
%N a(n+1) = a(n)*(a(n)+1).
%C The next term (a(8)) has 141 digits. - _Harvey P. Dale_, Jul 02 2021
%F a(n) = A082732(n+3) - 1. - _Max Alekseyev_, Aug 09 2019
%p A004168 := proc(n) option remember; if n=0 then 3 else A004168(n-1)*(A004168(n-1)+1); fi; end;
%t a = {3}; Do[AppendTo[a, a[[n - 1]] (a[[n - 1]] + 1)], {n, 2, 8}]; a (* _Michael De Vlieger_, Feb 23 2016 *)
%t NestList[#(#+1)&,3,7] (* _Harvey P. Dale_, Jul 02 2021 *)
%o (Magma) [n eq 1 select 3 else Self(n-1)*(Self(n-1)+1): n in [1..10]]; // _Vincenzo Librandi_, Feb 23 2016
%Y Cf. A000058, A007018.
%K nonn,easy
%O 0,1
%A _N. J. A. Sloane_
%E a(7) from _Vincenzo Librandi_, Feb 23 2016
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