%I #9 Sep 03 2017 03:28:13
%S 1,1,2,3,7,43,905,817217,222613996891,49556991610450473684541,
%T 350842202496894090472936261713260177362896247,
%U 123090251052871637971528096077183553457511351225922468278558723122652153910477674845042677
%N a(1) = a(2) = 1. a(n+1) = (Product_{k=1..floor(n/2)} a(k)) + (Product_{j=ceiling((n+1)/2)..n} a(j)).
%C a(13) has 177 digits. - _Emeric Deutsch_, Feb 06 2006
%e (1*1*2) + (3*8*50*1202) = 1442402.
%e a(8) = (a(1)*a(2)*a(3)) + (a(4)*a(5)*a(6)*a(7)) = (1*1*2) + (3*7*43*905) = 817217.
%p a[1]:=1: a[2]:=1: for n from 2 to 12 do a[n+1]:=product(a[k],k=1..floor(n/2))+product(a[j],j=1+floor(n/2)..n) od:seq(a[n],n=1..12); # _Emeric Deutsch_, Feb 06 2006
%K easy,nonn
%O 1,3
%A _Leroy Quet_, Jan 24 2006
%E Corrected and extended by _Emeric Deutsch_, Feb 06 2006