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Search: id:A137590
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| A137590 |
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Number of alternating full cycles on n letters. |
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+0
1
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| 1, 0, 1, 1, 3, 10, 39, 173, 882, 5052, 32163, 225230
(list; graph; listen)
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OFFSET
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1,5
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COMMENT
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a(n) is the number of full cycles pi of elements 1,2,...,n for which pi(1)<pi(2)>pi(3)<...
Calculations show that A000111(n)/n gives a highly good approximation to a(n). Examples: A000111(8)/8=1385/8=173.1 while a(8)=173; A000111(12)/12=225230.4 while a(12)=225230.
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REFERENCES
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V. Shevelev, On connection between the numbers of permutations and full cycles with some restrictions on positions and up-down structure, arXiv.org./abs/0803.2396
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CROSSREFS
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Cf. A000111, A129815, A129817.
Adjacent sequences: A137587 A137588 A137589 this_sequence A137591 A137592 A137593
Sequence in context: A063022 A063688 A083862 this_sequence A124532 A074728 A087860
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KEYWORD
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nonn
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AUTHOR
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Vladimir Shevelev (shevelev(AT)bgu.ac.il), Apr 26 2008
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