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Search: id:A145225
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| A145225 |
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T(n,k) is the number of odd permutations (of an n-set) with exactly k fixed points. |
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+0
1
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| 0, 0, 0, 1, 0, 0, 0, 3, 0, 0, 6, 0, 6, 0, 0, 20, 30, 0, 10, 0, 0, 135, 120, 90, 0, 15, 0, 0, 924, 945, 420, 210, 0, 21, 0, 0, 7420, 7392, 3780, 1120, 420, 0, 28, 0, 0, 66744, 66780, 33264, 11340, 2520, 756, 0, 36, 0, 0
(list; graph; listen)
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OFFSET
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0,8
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REFERENCES
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Ali, Bashir and Umar, A., "Some combinatorial properties of the alternating group". Southeast Asian Bulletin Math. 32 (2008), 823-830.
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FORMULA
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T(n,k)=C(n,k) A145221(n-k)
Egf.: (x^(k+2)e^(-x))/2(k!)(1-x)
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CROSSREFS
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Row sum is A001710 for n > 1, sum of Row1=sum of Row2 = 0.
T(n, 0) is A145221, T(n, 1) is A145222, T(n, 2) is A145223.
Sequence in context: A127773 A062688 A067181 this_sequence A061480 A048962 A135028
Adjacent sequences: A145222 A145223 A145224 this_sequence A145226 A145227 A145228
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KEYWORD
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nonn
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AUTHOR
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A. Umar (aumarh(AT)squ.edu.om), Oct 10 2008
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