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A096877
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Expansion of a parametrization of the Folium of Descartes.
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0
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1, -2, -10, 0, -130, 256, 236, 0, -22730, 81920, 327668, 0, 777260, 0, -7180840, 0, -1051237338, 4362076160, 22662123300, 0, 227431418372, -549755813888, -1598030872600, 0, -7086115747780, -32435593019392, -311555637408376, 0
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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COMMENTS
| Given g.f. A(x), then B(x)=xA(x^3/4) satisfies 0=f(B(x),B(x^2)) where f(u,v)=u^3+v^3-uv.
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EXAMPLE
| Series is x - 1/2*x^4 -5/8*x^7 -65/128*x^13 + ...
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PROG
| (PARI) a(n)=local(A, A2, m); if(n<0, 0, A=1+O(x); m=1; while(m<=n, m*=2; A=subst(A, x, 4*x^2); A2=subst(A, x, 4*x^2); A=sqrt(4*x^2*A2^2+A^3/A2)-2*x*A2); polcoeff(A, n))
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CROSSREFS
| Sequence in context: A189865 A189880 A189871 * A058297 A113160 A100078
Adjacent sequences: A096874 A096875 A096876 * A096878 A096879 A096880
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KEYWORD
| sign
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AUTHOR
| Michael Somos, Jul 14 2004
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