A099729 - OEIS

%I #9 Dec 18 2014 10:16:23

%S 1,2,8,68,4688,21977408,483006462403088,

%T 233295242723145661671791940368,

%U 54426670277251448804881298598338033107084297639402489952768

%N a(n) = a(n-1)^2 + a(floor(n/2))^2; a(0) = 1.

%H <a href="/index/Aa#AHSL">Index entries for sequences of form a(n+1)=a(n)^2 + ...</a>

%F a(n) ~ c^(2^n), where c = 1.6960426326108078452611100055735661068469295099996784988263600567400352165... . - _Vaclav Kotesovec_, Dec 18 2014

%t a = ConstantArray[0, 10]; a[[1]]=2; Do[a[[n]] = a[[n-1]]^2 + a[[Floor[n/2]]]^2,{n,2,10}]; Flatten[{1,a}] (* _Vaclav Kotesovec_, Dec 18 2014 *)

%Y Cf. A000123.

%K nonn

%O 0,2

%A _Reinhard Zumkeller_, Nov 08 2004