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A059418
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Triangle T(n,k) arising from enumeration of permutations with ordered orbits, read by rows (1<=k<=n).
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1
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1, 1, 1, 3, 2, 1, 12, 7, 4, 1, 60, 33, 19, 7, 1, 360, 192, 109, 47, 11, 1, 2520, 1320, 737, 344, 102, 16, 1, 20160, 10440, 5742, 2801, 956, 198, 22, 1, 181440, 93240, 50634, 25349, 9493, 2342, 352, 29, 1, 1814400, 927360, 498312, 253426, 101293, 28229
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 1,4
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REFERENCES
| L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 258, #10, F(n,k).
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FORMULA
| T(n, k) = (n-2)*T(n-1, k) + T(n-1, k-1), T(n, 1)=n!/2, T(n, n)=1.
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EXAMPLE
| 1; 1,1; 3,2,1; 12,7,4,1; 60,33,19,7,1; ...
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CROSSREFS
| Diagonals give A001710, A006595.
Sequence in context: A118435 A115085 A110616 * A092582 A068440 A048647
Adjacent sequences: A059415 A059416 A059417 * A059419 A059420 A059421
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KEYWORD
| nonn,easy,tabl
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), Jan 30 2001
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EXTENSIONS
| More terms from Larry Reeves (larryr(AT)acm.org), Jan 31 2001
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