login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Today, Nov 11 2014, is the 4th anniversary of the launch of the new OEIS web site. 70,000 sequences have been added in these four years, all edited by volunteers. Please make a donation (tax deductible in the US) to help keep the OEIS running.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A062298 Number of nonprimes <= n. 25
1, 1, 1, 2, 2, 3, 3, 4, 5, 6, 6, 7, 7, 8, 9, 10, 10, 11, 11, 12, 13, 14, 14, 15, 16, 17, 18, 19, 19, 20, 20, 21, 22, 23, 24, 25, 25, 26, 27, 28, 28, 29, 29, 30, 31, 32, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 42, 43, 43, 44, 45, 46, 47, 48, 48, 49, 50, 51, 51, 52, 52, 53 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

a(n) = n - A000720(n). This is asymptotic to n - Li(n). Note that A062298(n) + A095117(n) = 2*n. - Jonathan Vos Post, Nov 22 2004

LINKS

Harry J. Smith, Table of n, a(n) for n=1,...,1000

EXAMPLE

a(19) = 11 as there are 8 primes up to 19 (inclusive).

MAPLE

NumComposites := proc(N::posint) local count, i:count := 0:for i from 1 to N do if not isprime(i) then count := count + 1 fi:od: count; end:seq(NumComposites(binomial(k+1, k)), k=0..73); - Zerinvary Lajos, May 26 2008

A062298 := proc(n) n-numtheory[pi](n) ; end: seq(A062298(n), n=1..120) ; [From R. J. Mathar, Sep 27 2009]

MATHEMATICA

Table[n-PrimePi[n], {n, 80}] (* Harvey P. Dale, May 10 2012 *)

PROG

(PARI) { for (n=1, 1000, write("b062298.txt", n, " ", n-primepi(n)) ) } [From Harry J. Smith, Aug 04 2009]

(Haskell)

a062298 n = a062298_list !! (n-1)

a062298_list = scanl1 (+) $ map (1 -) a010051_list

-- Reinhard Zumkeller, Oct 10 2013

CROSSREFS

a(n)=n-A000720(n).

Cf. A101203, A010051.

Sequence in context: A174231 A072509 A197432 * A116579 A156253 A060151

Adjacent sequences:  A062295 A062296 A062297 * A062299 A062300 A062301

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Jun 19 2001

EXTENSIONS

Corrected and extended by Vladeta Jovovic, Jun 22 2001

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified November 28 13:03 EST 2014. Contains 250359 sequences.