%I #17 Sep 08 2022 08:46:15
%S 0,1,2,4,65536
%N a(n) = H_5(2,n) where H_n is the n-th hyperoperator.
%C See A054871 for definitions and key links.
%e a(-1)= H_5(2,-1)= 0;
%e a(0) = H_5(2,0) = 1;
%e a(1) = H_5(2,1) = 2;
%e a(2) = H_5(2,2) = H_4(2, H_4(2,1)) = H_4(2,2) = 2^2 = 4;
%e a(3) = H_5(2,3) = H_4(2, H_4(2,2)) = H_4(2,4) = 2^2^2^2 = 65536;
%o (Magma) [0] cat [n eq 1 select 1 else 2^Self(n-1)^(n-2): n in [1..4]]; // _Vincenzo Librandi_, Jan 18 2016
%Y Cf. A006263, A054871, A014221 (H_4(2,n)), A266199 (H_5(3,n)).
%K nonn
%O -1,3
%A _Natan Arie Consigli_, Jan 12 2016