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A292440 Expansion of (1 - x + sqrt(1 - 2*x - 3*x^2))/2 in powers of x. 1

%I

%S 1,-1,-1,-1,-2,-4,-9,-21,-51,-127,-323,-835,-2188,-5798,-15511,-41835,

%T -113634,-310572,-853467,-2356779,-6536382,-18199284,-50852019,

%U -142547559,-400763223,-1129760415,-3192727797,-9043402501,-25669818476,-73007772802

%N Expansion of (1 - x + sqrt(1 - 2*x - 3*x^2))/2 in powers of x.

%C Apart from a(1) the same as A168051. - _R. J. Mathar_, Sep 18 2017

%F Convolution inverse of A001006.

%F Let f(x) = (1 - x - sqrt(1 - 2*x - 3*x^2))/(2*x^2).

%F G.f.: 1-x-x^2/(1-x-x^2/(1-x-x^2/(1-x-x^2/(1-x-x^2/(... (continued fraction).

%F G.f.: 1/f(x) = 1 - x - x^2*f(x).

%F a(n) = -A001006(n-2) for n > 1.

%Y Cf. A001006, A086246.

%K sign

%O 0,5

%A _Seiichi Manyama_, Sep 16 2017

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Last modified February 24 05:37 EST 2018. Contains 299597 sequences. (Running on oeis4.)