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A028580
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C_{n+1}*C_n*C_{n-1}^2*C_{n-2}^4*...*C_2^{2^(n-2)}, where C_k are the Catalan numbers (A000108).
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1
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1, 2, 10, 280, 235200, 173859840000, 98238542885683200000000, 32169371027674057560745102540800000000000000000, 3518552669874927170883258602839130084576857453953842493259776000000000000000000000000000000000
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| Essentially the same as A003047. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 23 2008]
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REFERENCES
| D.-Z. Du and F. K. Hwang, Combinatorial Group Testing and Its Applications, World Scientific, 2nd ed., 2000; p. 36.
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FORMULA
| a(n) = 2*(2n-1)*a(n-1)^2/(n+1).
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CROSSREFS
| Sequence in context: A206158 A144288 A003047 * A171873 A098706 A143249
Adjacent sequences: A028577 A028578 A028579 * A028581 A028582 A028583
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KEYWORD
| nonn,easy
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), May 22 2000
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EXTENSIONS
| More terms from James A. Sellers (sellersj(AT)math.psu.edu), May 22 2000
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