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A328189
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Numbers n with at least one pair of consecutive divisible nontrivial divisors (greater than 1 and less than n).
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11
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8, 16, 18, 20, 27, 28, 32, 40, 42, 44, 50, 52, 54, 56, 64, 66, 68, 75, 76, 78, 80, 81, 88, 92, 98, 99, 100, 102, 104, 110, 112, 114, 116, 117, 124, 125, 126, 128, 130, 136, 138, 140, 147, 148, 152, 153, 156, 160, 162, 164, 170, 171, 172, 174, 176, 184, 186
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OFFSET
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1,1
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LINKS
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EXAMPLE
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The nontrivial divisors of 42 are {2, 3, 6, 7, 14, 21}, with pairs of consecutive divisible divisors {3, 6} and {7, 14}, so 42 belongs to the sequence.
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MATHEMATICA
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Select[Range[200], MatchQ[DeleteCases[Divisors[#], 1|#], {___, x_, y_, ___}/; Divisible[y, x]]&]
Select[Range[2, 200], AnyTrue[Partition[Most[Rest[Divisors[#]]], 2, 1], Mod[#[[2]], #[[1]]] == 0&]&] (* Harvey P. Dale, Mar 14 2023 *)
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CROSSREFS
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Positions of terms greater than 1 in A328194.
Partitions with a pair of consecutive divisible parts are A328221.
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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