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Search: id:A121948
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| A121948 |
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Floor of n-th 3-almost prime / n. |
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+0
1
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| 8, 6, 6, 5, 5, 4, 4, 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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3-almost prime analogue of A120927. The division is exact for n = 1, 2, 3, 4. for what n > 9 does a(n) drop below or rise above 4?
The division is exact for n = 1,2,3,4,73,113,163,173,263,499,557; no others up to 10000. First 3 after n=9 is a(109) = floor(435/109). Sequence then mixes 3's and 4's until a(557) = 4. It is then 3 for a long time, although a(812) = floor(3236/812) comes close to 4. Note that lim_{n->infinity} a(n) = infinity, although divergence is very slow. - Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Sep 20 2006
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FORMULA
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a(n) = Floor[(nth 3-almost prime)/n] = Floor[A014612(n)/n].
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EXAMPLE
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a(1) = Floor[8/1] = floor [8] = 8.
a(2) = Floor[12/2] = floor [6] = 6.
a(3) = Floor[18/3] = floor [6] = 6.
a(4) = Floor[20/4] = floor [5] = 5.
a(5) = Floor[27/5] = floor [5.4] = 5.
a(47) = Floor[190/47] = floor [4.0425531] = 4.
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CROSSREFS
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Cf. A014612, A120927.
Sequence in context: A102887 A067970 A003675 this_sequence A114141 A089139 A093209
Adjacent sequences: A121945 A121946 A121947 this_sequence A121949 A121950 A121951
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KEYWORD
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easy,nonn
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AUTHOR
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Jonathan Vos Post (jvospost3(AT)gmail.com), Sep 04 2006
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EXTENSIONS
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More terms from Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Sep 20 2006
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