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A008304 Triangle read by rows: T(n,k) (n>=1; 1<=k<=n) is the number of permutations of [n] in which the longest run has length k. 9
1, 1, 1, 1, 4, 1, 1, 16, 6, 1, 1, 69, 41, 8, 1, 1, 348, 293, 67, 10, 1, 1, 2016, 2309, 602, 99, 12, 1, 1, 13357, 19975, 5811, 1024, 137, 14, 1, 1, 99376, 189524, 60875, 11304, 1602, 181, 16, 1, 1, 822040, 1960041, 690729, 133669, 19710, 2360, 231, 18, 1, 1, 7477161 (list; table; graph; refs; listen; history; internal format)
OFFSET

1,5

COMMENTS

Row n has n terms.

REFERENCES

F. N. David, M. G. Kendall and D. E. Barton, Symmetric Function and Allied Tables, Cambridge, 1966, p. 261, Table 7.4.1.

LINKS

D. W. Wilson, Extended tables for A008304 and A064315

EXAMPLE

1; 1,1; 1,4,1; 1,16,6,1; 1,69,41,8,1; 1,348,293,67,10,1; ... T(3,2)=4 because we have (13)2, 2(13), (23)1, 3(12), where the parentheses surround runs of length 2.

CROSSREFS

Row sums give A064314. Cf. A064315.

Column k=2 yields A000303, column k=3 yields A000402, column 4 yields A000434.

Sequence in context: A155826 A010320 A152571 * A203846 A118185 A176483

Adjacent sequences:  A008301 A008302 A008303 * A008305 A008306 A008307

KEYWORD

tabl,nonn

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

More terms from David W. Wilson (davidwwilson(AT)comcast.net), Sep 07 2001

Better description from Emeric Deutsch (deutsch(AT)duke.poly.edu), May 08 2004

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Last modified February 17 08:44 EST 2012. Contains 205998 sequences.