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Search: id:A000402
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| A000402 |
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Number of permutations of [n] in which the longest run has length 3.
(Formerly M4239 N1771)
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+0
2
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| 1, 6, 41, 293, 2309, 19975, 189524, 1960041, 21993884, 266361634, 3465832370, 48245601976, 715756932697, 11277786883706, 188135296650845
(list; graph; listen)
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OFFSET
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3,2
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REFERENCES
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F. N. David, M. G. Kendall and D. E. Barton, Symmetric Function and Allied Tables, Cambridge, 1966, p. 261, Table 7.4.1.
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EXAMPLE
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a(4)=6 because we have (124)3, (134)2, (234)1, 4(123), 3(124), and 2(134), where the parentheses surround runs of length 3.
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CROSSREFS
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Cf. A008304.
Sequence in context: A049685 A122371 A083067 this_sequence A078009 A127848 A083161
Adjacent sequences: A000399 A000400 A000401 this_sequence A000403 A000404 A000405
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KEYWORD
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nonn
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AUTHOR
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njas
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EXTENSIONS
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Better description from Emeric Deutsch (deutsch(AT)duke.poly.edu), May 08 2004
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