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A161812
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Numbers with decreasing but not strictly decreasing prime signature.
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1
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6, 30, 36, 60, 120, 180, 210, 216, 240, 420, 480, 840, 900, 960, 1080, 1260, 1296, 1680, 1800, 1920, 2310
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| All numbers of the form 2^k1*3^k2*...*p_n^k_n, where k1 >= k2 >= ... >= k_n, and the '=' occurs at least once, sorted.
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EXAMPLE
| a(1) = 2*3, a(2) = 2*3*5, a(3) = 2^2*3^2, a(4) = 2^2*3*5.
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CROSSREFS
| Cf. A025487, A087980.
Sequence in context: A147798 A197880 A175497 * A188062 A056153 A062515
Adjacent sequences: A161809 A161810 A161811 * A161813 A161814 A161815
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KEYWORD
| easy,nonn
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AUTHOR
| Peter Luschny (peter(AT)luschny.de), Jun 20 2009
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