

A162177


a(n) is the number of composite numbers that are smaller than A008578(n).


3



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
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OFFSET

1,5


COMMENTS

Essentially the same as A065890.
a(n) = number of terms of A073169(n) less than n.


LINKS

Table of n, a(n) for n=1..62.


FORMULA

a(n) = A008578(n)  n = A158611(n+1) n.
a(n) = A065890(n1) for n > 1.


EXAMPLE

A008578(6) = 11, and there are 5 composites smaller than 11, viz. 4, 6, 8, 9, 10, hence a(6) = 5.


PROG

(MAGMA) T:=[0, 1] cat PrimesUpTo(300); [ T[n+1]n: n in [1..#T1] ]; // Klaus Brockhaus, Sep 08 2009


CROSSREFS

Cf. A002808 (composites), A008578 (1 and the primes), A065890, A073169.
Sequence in context: A000277 A003664 A065890 * A213730 A191172 A078632
Adjacent sequences: A162174 A162175 A162176 * A162178 A162179 A162180


KEYWORD

nonn,easy


AUTHOR

Jaroslav Krizek, Jun 27 2009


EXTENSIONS

Edited and extended by Klaus Brockhaus, Sep 09 2009


STATUS

approved



