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1, 3, 1, 15, 5, 2, 105, 35, 14, 8, 1155, 385, 154, 88, 48, 15015, 5005, 2002, 1144, 624, 480, 255255, 85085, 34034, 19448, 10608, 8160, 5760, 4849845, 1616615, 646646, 369512, 201552, 155040, 109440, 92160
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OFFSET
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1,2
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COMMENTS
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T(n,k) is the triangle in A174909 with reversed row order. (See that sequence for additional comments).
T(n,k) = number of terms with smallest prime factor prime(k) contained in primorial(n) consecutive numbers, k <= n. For example, T(5,4) = 88, so there are 88 terms with smallest prime factor 7 in any sequence of 2310 consecutive numbers.
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LINKS
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EXAMPLE
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Triangle starts:
n/k 1 2 3 4 5 6
1 1
2 3 1
3 15 5 2
4 105 35 14 8
5 1155 385 154 88 48
6 15015 5005 2002 1144 624 480
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MATHEMATICA
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Table[#1 Product[EulerPhi@ Prime@ i, {i, k - 1}]/#2 & @@ Map[Product[ Prime@ i, {i, #}] &, {n, k}], {n, 8}, {k, n}] // Flatten (* Michael De Vlieger, Oct 12 2017 *)
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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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