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A010030
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Triangle of permutations of 1..n by number of runs of consecutive pairs up and down (divided by 2).
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2
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1, 1, 0, 3, 0, 3, 8, 1, 25, 28, 7, 17, 155, 143, 45, 259, 1005, 933, 323, 131, 2770, 7488, 7150, 2621, 3177, 27978, 64164, 62310, 23811, 1281, 51433, 294602, 619986, 607445, 239653
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 1,4
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REFERENCES
| F. N. David, M. G. Kendall and D. E. Barton, Symmetric Function and Allied Tables, Cambridge, 1966, p. 264.
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FORMULA
| G.f. for number of permutations of 1..n by number of runs of consecutive pairs up and down is Sum(n!*(((1-y)*(2*x^2-x^3)-x)/((1-y)*x^2-1))^n,n = 0 .. infinity), cf. A010029. - Vladeta Jovovic (vladeta(AT)eunet.rs), Nov 23 2007
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CROSSREFS
| Cf. A002464, A001266, A000239, A000544, A001282.
Sequence in context: A021771 A154853 A139214 * A197270 A117940 A099093
Adjacent sequences: A010027 A010028 A010029 * A010031 A010032 A010033
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KEYWORD
| tabl,nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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EXTENSIONS
| More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Nov 23 2007
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