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A109777
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G.f. = f(x), where f(x)^2 = o.g.f. for A088313 (with offset 0).
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1
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1, 1, 3, 15, 101, 829, 7891, 84735, 1009065, 13170841, 186798003, 2859068831, 46960097413, 823787983021, 15370572776091, 303929827526887, 6348320745774993, 139663855708967665, 3227812335094695171, 78180132507785056399, 1980181972528939129861, 52344600987011191983613
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OFFSET
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0,3
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LINKS
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EXAMPLE
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The present sequence has g.f. f(x) = 1 + x + 3*x^2 + 15*x^3 + ...
A088313 [1,2,7,36,242,...] has e.g.f. = sinh(x/(1-x) = x + x^2 + 7/6*x^3 + 3/2*x^4 + 241/120*x^5 + 65/24*x^6 + 18271/5040*x^7 + ... and (with offset 0) o.g.f. = 1 + 2*x^2 +7*x^3 + 36*x^4 + ... = f(x)^2.
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MATHEMATICA
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nmax = 22;
f[x_] = Sqrt[Sum[SeriesCoefficient[Sinh[x/(1-x)], {x, 0, n}] n! x^n, {n, 0, nmax}]] + O[x]^nmax // Normal;
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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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