%I #5 Apr 30 2014 01:37:33
%S 1,1,1,2,13,867,12001543,4909644519038939,
%T 2976533007674072187623474816337374,
%U 5305128832761583696023807632374530398637482018663107882637653612424699
%N a(n) = (b(n+3) * b(n-1) * a(n-1)^2 - 1) / b(n+2) where b(n) = A006720(n).
%o (PARI) {a(n) = if( n<1, n>=0, (b(n+3) * b(n-1) * a(n-1)^2 - 1) / b(n+2))}
%Y Cf. A006720.
%K nonn,easy
%O 0,4
%A _Michael Somos_, Sep 20 2001
|