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A059446
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Triangle T(n,k) = coefficient of x^n*y^k/(n!*k!) in 1/(1-x-y-x*y), read by rows in order 00, 10, 01, 20, 11, 02, ...
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1
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1, 1, 1, 2, 3, 2, 6, 10, 10, 6, 24, 42, 52, 42, 24, 120, 216, 300, 300, 216, 120, 720, 1320, 1968, 2268, 1968, 1320, 720, 5040, 9360, 14640, 18576, 18576, 14640, 9360, 5040, 40320, 75600, 122400, 166320, 184896, 166320, 122400, 75600
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OFFSET
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0,4
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LINKS
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FORMULA
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E.g.f.: 1/(1-x-y-x*y).
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EXAMPLE
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1; 1,1; 2,3,2; 6,10,10,6; ...
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MAPLE
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read transforms; SERIES2(1/(1-x-y-x*y), x, y, 12): SERIES2TOLISTMULT(%, x, y, 12);
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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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