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A119827
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Number of ternary words with exactly one 000.
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2
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0, 0, 0, 1, 4, 16, 60, 212, 728, 2444, 8064, 26256, 84576, 270048, 855936, 2696080, 8446912, 26341696, 81812544, 253181888, 781005440, 2402311616, 7370247168, 22558917120, 68901651456, 210037106688, 639127277568, 1941624275200
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,5
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COMMENTS
| Except for the initial three zeros, convolution of A077835 with itself. Column 1 of A119825.
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FORMULA
| G.f.=z^3/(1-2z-2z^2-2z^3)^2.
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EXAMPLE
| a(4)=4 because we have 0001, 0002, 1000 and 2000.
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MAPLE
| h:=z^3/(1-2*z-2*z^2-2*z^3)^2: hser:=series(h, z=0, 33): seq(coeff(hser, z, n), n=0..30);
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CROSSREFS
| Cf. A077835, A119825, A119826.
Sequence in context: A032094 A055295 A121254 * A089883 A089932 A120926
Adjacent sequences: A119824 A119825 A119826 * A119828 A119829 A119830
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KEYWORD
| nonn
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AUTHOR
| Emeric Deutsch (deutsch(AT)duke.poly.edu), May 26 2006
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