A143849 Let x(1) = 1 and x(n) = x(n-1)^2 + i for n>1; a(n) is the imaginary part of x(n).

0, 1, 3, 1, -17, -2719, -33231617, -1990664248298239, 825155821714086784897292716543, -6468873315977272230111786035347284128217298704834756326835199

Offset: 1

Author

Reinhard Zumkeller, Sep 03 2008

Keywords

• sign

Examples

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

Crossrefs

A143848 gives the read part of x(n).

Formula

a(n+1) = 2*a(n)*A143848(n) + 1.

Extensions

Definition clarified by N. J. A. Sloane, Jul 11 2024 at the suggestion of Harvey P. Dale.