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A320808
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Regular tetrangle where T(n,k,i) is the number of nonnegative integer matrices up to row and column permutations with no zero rows or columns and k nonzero entries summing to n, with i columns.
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12
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1, 0, 0, 1, 0, 0, 1, 0, 1, 2, 0, 0, 1, 0, 1, 2, 0, 1, 2, 3, 0, 0, 1, 0, 2, 4, 0, 1, 5, 4, 0, 1, 5, 5, 5, 0, 0, 1, 0, 2, 4, 0, 2, 10, 8, 0, 1, 9, 13, 7, 0, 1, 5, 12, 9, 7, 0, 0, 1, 0, 3, 6, 0, 3, 16, 12, 0, 2, 24, 33, 16, 0, 1, 14, 36, 29, 12, 0, 1, 9, 23, 29
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OFFSET
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1,10
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LINKS
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EXAMPLE
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Tetrangle begins:
1 0 0 0 0 0
0 1 0 1 0 1 0 1 0 1
0 1 2 0 1 2 0 2 4 0 2 4
0 1 2 3 0 1 5 4 0 2 10 8
0 1 5 5 5 0 1 9 13 7
0 1 5 12 9 7
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CROSSREFS
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Triangle sums are A007716. Triangle of row sums is A320801. Triangle of column sums is A317533. Triangle of last columns (without its leading column 1,0,0,0,...) is A055884.
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KEYWORD
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nonn,tabf
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AUTHOR
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STATUS
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approved
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