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A255912
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O.g.f.: exp( Sum_{n>=1} A000364(2*n)*x^n/n ), where A000364 is the Euler numbers.
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0
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1, 5, 705, 904405, 4852631105, 74099113400805, 2586129891894933505, 178907219873738420449205, 22190820320340007699602667905, 4580340005051337829651272441809605, 1485137988777113358037521465779043594305, 722514649061693644099760448944719529057242005
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OFFSET
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0,2
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COMMENTS
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a(n) == 5 (mod 100) for n>=1 (conjecture).
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LINKS
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EXAMPLE
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O.g.f.: A(x) = 1 + 5*x + 705*x^2 + 904405*x^3 + 4852631105*x^4 +...
where
log(A(x)) = 5*x + 1385*x^2/2 + 2702765*x^3/3 + 19391512145*x^4/4 + 370371188237525*x^5/5 + 15514534163557086905*x^6/6 + +...+ A000364(2*n)*x^n/n +...
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PROG
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(PARI) /* By definition */
{A000364(n)=polcoeff(sum(m=0, n, (2*m)!/2^m * x^m/prod(k=1, m, 1+k^2*x+x*O(x^n))), n)}
{a(n)=local(A=1); A=exp(sum(m=1, n, A000364(2*m)*x^m/m) +x*O(x^n)); polcoeff(A, n)}
for(n=0, 20, 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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