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A205804
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E.g.f.: -log( Sum_{n>=0} (-x)^(n^2) / (n^2)! ).
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4
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1, 1, 2, 5, 19, 90, 510, 3395, 25831, 221140, 2104310, 22027170, 251540795, 3111928820, 41460769350, 591847005749, 9011786683883, 145794610986004, 2497443795363566, 45157627509568965, 859494143391347310, 17176870199851102510, 359623890969235361700
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OFFSET
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1,3
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LINKS
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EXAMPLE
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E.g.f.: A(x) = x + x^2/2! + 2*x^3/3! + 5*x^4/4! + 19*x^5/5! + 90*x^6/6! +...
where
exp(-A(x)) = 1 - x + x^4/4! - x^9/9! + x^16/16! - x^25/25! + x^36/36! +...
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PROG
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(PARI) {a(n) = n!*polcoeff(-log(sum(m=0, sqrtint(n+1), (-x)^(m^2)/(m^2)!+x*O(x^n))), n)}
for(n=1, 25, print1(a(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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