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Search: id:A000506
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| A000506 |
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One half of the number of permutations of [n] such that the differences have 5 runs with the same signs.
(Formerly M5322 N2313)
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+0
3
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| 61, 841, 7311, 51663, 325446, 1910706, 10715506, 58258210, 309958755, 1623847695, 8412276585, 43220104041, 220683627988, 1121561317408, 5679711010548, 28683869195556, 144552802373145, 727271783033445
(list; graph; listen)
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OFFSET
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6,1
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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. 260.
L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 260, #13
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FORMULA
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16*a(n)/5^n ->1 as n ->infinity . - DELEHAM Philippe (kolotoko(AT)wanadoo.fr), Feb 22 2004
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CROSSREFS
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A diagonal of A008970.
Sequence in context: A086945 A142365 A093473 this_sequence A008358 A138790 A057534
Adjacent sequences: A000503 A000504 A000505 this_sequence A000507 A000508 A000509
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KEYWORD
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nonn,easy
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AUTHOR
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njas
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EXTENSIONS
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More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu), Feb 21 2004
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