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A127123
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Triangle read by rows: T(n,k) = number of endofunctions on n points with k points in the image.
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0
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1, 1, 2, 1, 3, 3, 1, 6, 7, 5, 1, 7, 18, 14, 7, 1, 10, 33, 49, 26, 11, 1, 11, 52, 110, 109, 45, 15, 1, 14, 75, 221, 314, 229, 75, 22, 1, 15, 105, 372, 746, 788, 438, 120, 30, 1, 18, 136, 601, 1508, 2222, 1797, 806, 187, 42, 1, 19, 174, 888, 2763, 5208, 5888, 3806, 1404, 284, 56
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listen;
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text;
internal format)
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OFFSET
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1,3
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LINKS
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EXAMPLE
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For n = 3, the 7 endofunctions are (1,2,3) -> (1,1,1), (1,1,2), (1,2,1), (2,1,1), (1,2,3), (1,3,2) and (2,3,1). The number of points in the image are respectively 1,2,2,2,3,3,3, so row 3 is 1,3,3.
The triangle starts:
1
1 2
1 3 3
1 6 7 5
1 7 18 14 7
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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