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A136181
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Irregular array read by rows: row n contains the LCMs of each pair of consecutive positive divisors of n.
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5
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2, 3, 2, 4, 5, 2, 6, 6, 7, 2, 4, 8, 3, 9, 2, 10, 10, 11, 2, 6, 12, 12, 12, 13, 2, 14, 14, 3, 15, 15, 2, 4, 8, 16, 17, 2, 6, 6, 18, 18, 19, 2, 4, 20, 10, 20, 3, 21, 21, 2, 22, 22, 23, 2, 6, 12, 12, 24, 24, 24, 5, 25, 2, 26, 26, 3, 9, 27, 2, 4, 28, 14, 28, 29, 2, 6, 15, 30, 30, 30, 30, 31, 2, 4
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 2,1
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COMMENTS
| Each row has d(n)-1 terms, where d(n) is the number of positive divisors of n. The first row listed is row 2.
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LINKS
| Diana Mecum, Table of n, a(n) for n=2,...,6070
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EXAMPLE
| The positive divisors of 20 are 1,2,4,5,10,20. LCM(1,2)=2. LCM(2,4)=4. LCM(4,5)=20. LCM(5,10)=10. And LCM(10,20)=20. So row 20 is (2,4,20,10,20).
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MATHEMATICA
| Flatten[Table[LCM@@@(Partition[Divisors[n], 2, 1]), {n, 2, 35}]] (* From Harvey P. Dale, Apr 22 2011 *)
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CROSSREFS
| Cf. A136178, A136182, A136183.
Sequence in context: A120499 A027749 A029638 * A003976 A172520 A161908
Adjacent sequences: A136178 A136179 A136180 * A136182 A136183 A136184
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KEYWORD
| nonn,tabl
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AUTHOR
| Leroy Quet Dec 19 2007
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EXTENSIONS
| Added terms a(24) - a(6069). - Diana Mecum (diana.mecum(AT)gmail.com), Dec 29 2008
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