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!)
A127197 Numerator of n-th Van der Waerden-Ulam binary measure of the primes. 2
1, 1, 1, 3, 3, 1, 1, 1, 1, 5, 5, 3, 3, 3, 3, 7, 7, 1, 1, 1, 1, 9, 9, 9, 9, 9, 9, 5, 5, 11, 11, 11, 11, 11, 11, 3, 3, 3, 3, 13, 13, 7, 7, 7, 7, 15, 15, 15, 15, 15, 15, 1, 1, 1, 1, 1, 1, 17, 17, 9, 9, 9, 9, 9, 9, 19, 19, 19, 19, 5, 5, 21, 21, 21, 21, 21, 21, 11, 11, 11, 11, 23, 23, 23, 23, 23, 23 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,4

LINKS

Table of n, a(n) for n=2..88.

MATHEMATICA

Table[Numerator[PrimePi[k]/2^k], {k, 2, 1000}]

PROG

(PARI) a(n) = numerator(primepi(n)/2^n); \\ Michel Marcus, Oct 28 2019

CROSSREFS

Cf. A000079 (2^n), A000720 (PrimePi), A119523.

Sequence in context: A046533 A046532 A014421 * A114231 A079075 A086703

Adjacent sequences:  A127194 A127195 A127196 * A127198 A127199 A127200

KEYWORD

nonn,frac

AUTHOR

Artur Jasinski, Jan 08 2007

EXTENSIONS

Offset 2 from Michel Marcus, Oct 28 2019

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 June 5 01:27 EDT 2020. Contains 334828 sequences. (Running on oeis4.)