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A049644
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T(n,n), array T given by A049639.
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1
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0, 0, 3, 3, 5, 5, 9, 9, 13, 13, 21, 21, 25, 25, 37, 37, 45, 45, 57, 57, 65, 65, 85, 85, 93, 93, 117, 117, 129, 129, 145, 145, 161, 161, 193, 193, 205, 205, 241, 241, 257, 257, 281, 281, 301, 301, 345, 345, 361, 361, 401, 401, 425, 425, 461, 461, 485, 485, 541, 541, 557, 557
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OFFSET
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0,3
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LINKS
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MATHEMATICA
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a[0 | 1, 0 | 1] = 0; a[0 | 1, _] = a[_, 0 | 1] = 1; a[i_, j_] := Module[{slopes, cnt}, slopes = Union@Flatten@Table[(k - j)/(h - i), {h, 0, i - 1}, {k, 0, j - 1}]; cnt[slope_] := Count[Flatten[Table[{h, k}, {h, 0, i - 1}, {k, 0, j - 1}], 1], {h_, k_} /; (k - j)/(h - i) == slope]; Count[cnt /@ slopes, c_ /; c >= 2] + 2]; Table[a[n, n], {n, 0, 25}] (* G. C. Greubel, Dec 07 2017 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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