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%I #4 Dec 15 2012 11:14:26
%S 2,7,41,1723,2967005,8803121637031,77494950556354550188857929
%N Recursive form of A109845 without a(2)=3.
%F a(1)=2, a(n)=a(n-1)^2+(-1)^n*a(n-1)+(-1)^n
%p a := proc(n) option remember; if n=1 then 2 else a(n-1)^2+(-1)^n*a(n-1)+(-1)^n fi end:
%t nxt[{n_,a_}]:={n+1,a^2+(-1)^(n+1) a+(-1)^(n+1)}; Transpose[NestList[nxt,{1,2},10]][[2]] (* _Harvey P. Dale_, Dec 15 2012 *)
%Y Cf. A109845.
%K nonn
%O 1,1
%A _Walter Kehowski_, Aug 18 2005
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