A143848 - OEIS

A143848

Let x(1) = 1 and x(n) = x(n-1)^2 + i for n>1; a(n) is the real part of x(n).

%I #12 Jul 11 2024 21:44:26

%S 1,1,0,-9,80,6111,29951360,-207256402585089,

%T -3919788933040280447085605363200,

%U 14683863149476410414382246646213355893861151824423487368369151

%N Let x(1) = 1 and x(n) = x(n-1)^2 + i for n>1; a(n) is the real part of x(n).

%F a(n+1) = a(n)^2 - A143849(n)^2.

%e The x(n) sequence starts 1, 1+i, 3*i, -9+i, 80-17*i, 6111-2719*i, ...

%Y A143849 gives the imaginary part of x(n).

%K sign

%O 1,4

%A _Reinhard Zumkeller_, Sep 03 2008

%E Definition clarified by _N. J. A. Sloane_, Jul 11 2024 at the suggestion of _Harvey P. Dale_.