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A143135
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E.g.f. satisfies: A(x) = sin(x + A(x)^2) with A(0)=0.
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4
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1, 2, 11, 100, 1261, 20342, 399671, 9256840, 246907321, 7452534122, 251099460611, 9341422237420, 380293239870181, 16815919738248542, 802553031266952431, 41117164304824602640, 2250747364089063475441
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OFFSET
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1,2
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COMMENTS
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Radius of convergence of A(x) is r = Pi/4 - 1/2, with A(r) = sqrt(2)/2.
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LINKS
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FORMULA
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E.g.f.: A(x) = sin(G(x)) where G(x) = x + A(x)^2 is the e.g.f. of A143134.
E.g.f. derivative: A'(x) = sqrt(1 - A(x)^2)/(1 - 2*A(x)*sqrt(1 - A(x)^2)).
a(n) ~ GAMMA(1/3) * 4^(n-1) * n^(n-5/6) / (3^(1/6) * sqrt(Pi) * exp(n) * (Pi-2)^(n-1/3)). - Vaclav Kotesovec, Jan 19 2014
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EXAMPLE
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A(x) = x + 2*x^2/2! + 11*x^3/3! + 100*x^4/4! + 1261*x^5/5! +...
A(x) = sin(G(x)) where G(x) = x + A(x)^2 is the e.g.f. of A143134:
G(x) = x + 2*x^2/2! + 12*x^3/3! + 112*x^4/4! + 1440*x^5/5! +...
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MATHEMATICA
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Rest[CoefficientList[InverseSeries[Series[-x^2 + ArcSin[x], {x, 0, 20}], x], x] * Range[0, 20]!] (* Vaclav Kotesovec, Jan 19 2014 *)
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PROG
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(PARI) {a(n)=local(A=x); for(i=0, n, A=x + sin(A)^2); n!*polcoeff(sin(A), n)}
(PARI) {a(n)=n!*polcoeff(sin(serreverse(x-sin(x+x*O(x^n))^2)), n)}
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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