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Search: id:A162177
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| A162177 |
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a(n) = number of composite numbers that are smaller than A008578(n). |
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+0
4
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| 0, 0, 0, 1, 2, 5, 6, 9, 10, 13, 18, 19, 24, 27, 28, 31, 36, 41, 42, 47, 50, 51, 56, 59, 64, 71, 74, 75, 78, 79, 82, 95, 98, 103, 104, 113, 114, 119, 124, 127, 132, 137, 138, 147, 148, 151, 152, 163, 174, 177, 178, 181, 186, 187, 196, 201, 206, 211, 212, 217, 220, 221
(list; graph; listen)
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OFFSET
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1,5
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COMMENT
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Here offset 1 is assumed for A008578.
Essentially the same as A065890.
a(n) = A008578(n) - n.
a(n) = number of terms of A073169(n) less than n.
a(n) = A065890(n-1) for n > 1.
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EXAMPLE
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A008578(6) = 11, and there are 5 composites smaller than 11, viz. 4, 6, 8, 9, 10, hence a(6) = 5.
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PROGRAM
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(MAGMA) T:=[0, 1] cat PrimesUpTo(300); [ T[n+1]-n: n in [1..#T-1] ]; [From Klaus Brockhaus, Sep 08 2009]
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CROSSREFS
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Cf. A002808 (composites), A008578 (1 and the primes), A000040 (primes), A065890 (number of composites less than n-th prime), A073169 (difference between n-th composite and n).
Sequence in context: A000277 A003664 A065890 this_sequence A078632 A122701 A032925
Adjacent sequences: A162174 A162175 A162176 this_sequence A162178 A162179 A162180
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KEYWORD
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nonn
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AUTHOR
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Jaroslav Krizek (jaroslav.krizek(AT)atlas.cz), Jun 27 2009
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EXTENSIONS
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Edited and extended by Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Sep 09 2009
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