1,2

a(1) = 1, a(n)=a(n-1)^2+(-1)^n*a(n-1)+(-1)^n

a := proc(n) option remember; if n=1 then 1 else a(n-1)^2+(-1)^n*a(n-1)+(-1)^n fi end:

Cf. A109845.

Sequence in context: A106893 A047105 A136361 this_sequence A103010 A068111 A162444

Adjacent sequences: A109170 A109171 A109172 this_sequence A109174 A109175 A109176

nonn

Walter A. Kehowski (wkehowski(AT)cox.net), Aug 18 2005