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A085578
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Array read by antidiagonals: T(m,n) is the number of distinct products ij with 1<=i<=m, i<=j<=n, for m>=1, n>=1.
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0
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1, 2, 2, 3, 3, 3, 4, 5, 5, 4, 5, 6, 6, 6, 5, 6, 8, 8, 8, 8, 6, 7, 9, 11, 9, 11, 9, 7, 8, 11, 12, 13, 13, 12, 11, 8, 9, 12, 15, 15, 14, 15, 15, 12, 9, 10, 14, 17, 19, 17, 17, 19, 17, 14, 10, 11, 15, 18, 20, 22, 18, 22, 20, 18, 15, 11, 12, 17, 20, 22, 24, 24, 24, 24, 22, 20, 17, 12, 13, 18, 23, 24, 27, 27, 25, 27, 27, 24, 23, 18, 13
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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EXAMPLE
| Array begins:
1 2 3 4 5 6 7 8 9 10 ...
2 3 5 6 8 9 11 12 14 15 ...
3 5 6 8 11 12 15 17 18 20 ...
4 6 8 9 13 15 19 20 22 24 ...
5 8 11 13 14 17 22 24 27 28 ...
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MAPLE
| T := (m, n) -> nops({seq(seq(i*j, i=1..m), j=1..n)});
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MATHEMATICA
| T[m_, n_] := Length[Union @@ Table[i*j, {i, m}, {j, n}]]
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CROSSREFS
| A027424 is the main diagonal.
Sequence in context: A194311 A134403 A124882 * A135646 A101646 A166079
Adjacent sequences: A085575 A085576 A085577 * A085579 A085580 A085581
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KEYWORD
| nonn,tabl
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AUTHOR
| Michael Kleber (michael.kleber(AT)gmail.com), Jul 09 2003
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