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Search: id:A156992
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| A156992 |
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A triangular sequence:t(n,m)=n!*Binomial[n - 1, m - 1]. |
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+0
1
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| 1, 2, 2, 6, 12, 6, 24, 72, 72, 24, 120, 480, 720, 480, 120, 720, 3600, 7200, 7200, 3600, 720, 5040, 30240, 75600, 100800, 75600, 30240, 5040, 40320, 282240, 846720, 1411200, 1411200, 846720, 282240, 40320, 362880, 2903040, 10160640, 20321280
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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Row sums are:A002866
{1, 4, 24, 192, 1920, 23040, 322560, 5160960, 92897280, 1857945600,...}.
This sequence is the ordered occupancy with no cell empty form from Riordan.
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REFERENCES
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J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 98
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FORMULA
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t(n,m)=n!*Binomial[n - 1, m - 1].
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EXAMPLE
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{1},
{2, 2},
{6, 12, 6},
{24, 72, 72, 24},
{120, 480, 720, 480, 120},
{720, 3600, 7200, 7200, 3600, 720},
{5040, 30240, 75600, 100800, 75600, 30240, 5040},
{40320, 282240, 846720, 1411200, 1411200, 846720, 282240, 40320},
{362880, 2903040, 10160640, 20321280, 25401600, 20321280, 10160640, 2903040, 362880}, {3628800, 32659200, 130636800, 304819200, 457228800, 457228800, 304819200, 130636800, 32659200, 3628800}
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MATHEMATICA
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Clear[t, n, m];
t[n_, m_] = n!*Binomial[n - 1, m - 1];
Table[Table[t[n, m], {m, 1, n}], {n, 1, 10}];
Flatten[%]
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CROSSREFS
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A002866
Sequence in context: A036052 A091764 A079005 this_sequence A054481 A157285 A035615
Adjacent sequences: A156989 A156990 A156991 this_sequence A156993 A156994 A156995
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KEYWORD
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nonn,tabf,uned
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AUTHOR
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Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Feb 20 2009
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