login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A038801 Number of primes less than 10n. 23
4, 8, 10, 12, 15, 17, 19, 22, 24, 25, 29, 30, 31, 34, 35, 37, 39, 41, 42, 46, 46, 47, 50, 52, 53, 55, 57, 59, 61, 62, 63, 66, 66, 68, 70, 72, 73, 75, 77, 78, 80, 81, 82, 85, 87, 88, 91, 92, 93, 95, 97, 97, 99, 99, 101, 102, 104, 106, 107, 109, 111, 114, 114, 115, 118, 120 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

For almost all n, that is for a set of density 1, a(n) = a(n-1), and in all cases a(n) <= a(n-1) + 4. - Charles R Greathouse IV, Aug 27 2014

LINKS

Robert G. Wilson v, Table of n, a(n) for n = 1..10000

Andrew R. Booker, The Nth Prime Page

Thomas R. Nicely, Some Results of Computational Research in Prime Numbers

Tomás Oliveira e Silva, Tables of values of pi(x) and of pi2(x)

MATHEMATICA

Table[ PrimePi[ n*10 ], {n, 1, 66}] (* Robert G. Wilson v *)

PROG

(PARI) a(n)=primepi(10*n) \\ Charles R Greathouse IV, Aug 27 2014

CROSSREFS

Cf. A028505, A038812, A038813, A038814, A038815, A038816, A038817, A038818, A038819, A038820, A038821, A080122, A080123, A080124, A080125, A080126, A080127, A080128, A080129.

Sequence in context: A175226 A057166 A230854 * A310977 A337813 A310978

Adjacent sequences:  A038798 A038799 A038800 * A038802 A038803 A038804

KEYWORD

nonn

AUTHOR

Jeff Burch

EXTENSIONS

Edited and corrected by Robert G. Wilson v, Jan 29 2003

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 13 15:23 EDT 2021. Contains 342936 sequences. (Running on oeis4.)