%I A007449 M4337
%S A007449 7,9,40,74,1526,5436,2323240,29548570,5397414549030,873117986721660,
%T A007449 29132083813207600287219240,762335018736884842676898606570,
%U A007449 848678307299752276902028307632840866100214927571030
%N A007449 a(0) = 7, a(1) = 9; for n >= 0, a(2n+1) = a(2n-1)^2 - a(2n-2), a(2n+2) 
               = a(2n)^2 - a(2n+1).
%D A007449 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A007449 Intelligence test in Chess Life, Vol. 49(#6) 1994, p. 14.
%F A007449 a(n+1) = a(n-1)^2 - a(n - 2*(1 - n mod 2)), a(0)=7, a(1)=9. - Reinhard 
               Zumkeller (reinhard.zumkeller(AT)gmail.com), Mar 25 2003
%o A007449 (PARI) a(n)=if(n<0,0,if(n<2,[7,9][n+1],a(n-2)^2-a(n-2+(-1)^n)))
%Y A007449 Sequence in context: A057590 A140787 A032695 this_sequence A067649 A025631 
               A038275
%Y A007449 Adjacent sequences: A007446 A007447 A007448 this_sequence A007450 A007451 
               A007452
%K A007449 nonn,easy
%O A007449 0,1
%A A007449 N. J. A. Sloane (njas(AT)research.att.com).
%E A007449 More terms from Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), 
               Mar 25 2003