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Search: id:A124283
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| A124283 |
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4-almost primes indexed by primes. |
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+0
8
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| 24, 36, 54, 60, 90, 104, 136, 150, 189, 225, 232, 294, 308, 328, 344, 375
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Primes indexed by 4-almost primes = A124282. prime(4almostprime(n)) - 4almostprime(prime(n)) = A124284. Primes indexed by 3-almost primes = A124268. 3-almost primes indexed by primes = A124269. prime(3almostprime(n)) - 3almostprime(prime(n)) = A124270. See also A106349 Primes indexed by semiprimes. See also A106350 Semiprimes indexed by primes. See also A122824 Prime(semiprime(n)) - semiprime(prime(n)). Commutator [A000040,A001358] at n.
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FORMULA
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a(n) = 4almostprime(prime(n)) = A014613(A000040(n)).
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EXAMPLE
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a(1) = 4almostprime(prime(1)) = 4almostprime(2) = 24.
a(2) = 4almostprime(prime(2)) = 4almostprime(3) = 36.
a(3) = 4almostprime(prime(3)) = 4almostprime(5) = 54.
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CROSSREFS
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Cf. A000040, A014613, A114414, A122824, A124269, A124270, A124282, A124284.
Sequence in context: A067766 A078347 A165602 this_sequence A143645 A003176 A003138
Adjacent sequences: A124280 A124281 A124282 this_sequence A124284 A124285 A124286
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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), Oct 24 2006
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