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%I #11 Jan 11 2020 15:57:47
%S 1,3,3,27,19683,
%T 87189642485960958202911070585860771696964072404731750085525219437990967093723439943475549906831683116791055225665627
%N a(1) = 1, a(2) = 3, a(n) = a(n-1)^a(n-2).
%t a[1] = 1; a[2] = 3; a[n_] := a[n] = a[n - 1]^a[n - 2]; Array[a, {6}] (* _Michael De Vlieger_, Apr 17 2016 *)
%Y Cf. A264932 with a(n-1)^^a(n-2) or a(n-1)^a(n-2)^a(n-2);
%Y Cf. A051285 (with a(2) = 2).
%K nonn
%O 1,2
%A _Natan Arie Consigli_, Apr 17 2016