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Search: id:A073178
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| A073178 |
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a(n) = n!^2 times coefficient of x^n in e^(x*(3-x)/2/(1-x))/(1-x)^(1/2). |
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+0
2
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| 1, 2, 13, 180, 4266, 153180, 7725510, 519629040, 44880355800, 4835536256880, 635221698211800, 99872627051181600, 18507444606249152400, 3990439472567239692000, 990119486841576670378800
(list; graph; listen)
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OFFSET
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0,2
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REFERENCES
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R. P. Stanley, Enumerative Combinatorics, Cambridge, Vol. 2, 1999; see Problem 5.65(b).
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FORMULA
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e^(x*(3-x)/2/(1-x))/(1-x)^(1/2) = Sum_{n>=0} a(n)*x^n/n!^2. - Vladeta Jovovic (vladeta(AT)eunet.rs), Aug 01 2006
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PROGRAM
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(PARI) a(n)=if(n<0, 0, n!^2*polcoeff(exp(x*(3-x)/2/(1-x)+x*O(x^n))/sqrt(1-x+x*O(x^n)), n))
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CROSSREFS
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Cf. A049088.
Adjacent sequences: A073175 A073176 A073177 this_sequence A073179 A073180 A073181
Sequence in context: A006905 A119400 A137610 this_sequence A062156 A049512 A003507
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KEYWORD
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nonn
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AUTHOR
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Michael Somos, Jul 19 2002
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