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A050436
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Third-order composites.
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6
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16, 21, 25, 26, 28, 33, 36, 38, 39, 42, 48, 49, 50, 52, 55, 56, 57, 60, 64, 68, 69, 70, 72, 74, 77, 78, 80, 84, 87, 88, 90, 93, 94, 95, 98, 100, 104, 105, 106, 110, 111, 115, 117, 118, 119, 121, 122, 124, 125, 126, 130, 133, 135, 138, 140, 141, 145, 146, 147
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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LINKS
| N. Fernandez, An order of primeness, F(p)
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FORMULA
| Let C(n) be the n-th composite number, with C(1)=4. Then these are numbers C(C(C(n))).
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EXAMPLE
| C(C(C(8))) = C(C(15)) = C(25) = 38. So 38 is in the sequence.
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MAPLE
| C := remove(isprime, [$4..1000]): seq(C[C[C[C[n]]]], n=1..100);
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CROSSREFS
| A049076-A049081, A006450, A050435, A050438, ...
Sequence in context: A205098 A165160 A180411 * A038868 A186454 A138173
Adjacent sequences: A050433 A050434 A050435 * A050437 A050438 A050439
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KEYWORD
| easy,nonn
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AUTHOR
| Michael Lugo (mlugo(AT)thelabelguy.com), Dec 22 1999
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EXTENSIONS
| More terms from Asher Auel (asher.auel(AT)reed.edu) Dec 15 2000
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