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A084890
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Triangular array, read by rows: T(n,k) = arithmetic derivative of n*k, 1<=k<=n.
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3
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0, 1, 4, 1, 5, 6, 4, 12, 16, 32, 1, 7, 8, 24, 10, 5, 16, 21, 44, 31, 60, 1, 9, 10, 32, 12, 41, 14, 12, 32, 44, 80, 68, 112, 92, 192, 6, 21, 27, 60, 39, 81, 51, 156, 108, 7, 24, 31, 68, 45, 92, 59, 176, 123, 140, 1, 13, 14, 48, 16, 61, 18, 140, 75, 87, 22, 16, 44, 60, 112, 92, 156, 124, 272, 216, 244, 188, 384
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OFFSET
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1,3
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LINKS
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FORMULA
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EXAMPLE
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................. 0
.............. 1 ... 4
........... 1 ... 5 ... 6
........ 4 .. 12 .. 16 .. 32
..... 1 ... 7 ... 8 .. 24 .. 10
.. 5 .. 16 .. 21 .. 44 .. 31 .. 60
1 ... 9 .. 10 .. 32 .. 12 .. 41 .. 14.
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MATHEMATICA
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ader[n_] := ader[n] =Switch[n, 0 | 1, 0, _, If[PrimeQ[n], 1, Sum[Module[{p, e}, {p, e} = pe; n e/p], {pe, FactorInteger[n]}]]];
T[n_, k_] := ader[n k];
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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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