login
a(n) = H_{n-1}(n,n).
2

%I #6 Jan 11 2020 15:57:47

%S 1,2,4,9,64

%N a(n) = H_{n-1}(n,n).

%C H is the hyperoperation function see A054871 for more information.

%C This sequence is a shifted version of the weak Ackermann numbers H_n(n,n).

%Y Cf. A189896 (H_n(n,n)), A054871.

%K nonn,bref

%O 0,2

%A _Natan Arie Consigli_, Apr 09 2016