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!)
A127201 Base-2 logarithms of denominators corresponding to A127200. 1
2, 1, 3, 5, 6, 6, 4, 7, 8, 11, 12, 11, 13, 14, 15, 17, 18, 18, 18, 16, 19, 23, 24, 25, 26, 27, 28, 26, 29, 31, 32, 33, 34, 35, 36, 36, 35, 37, 38, 41, 42, 41, 43, 44, 45, 47, 48, 49, 50, 51, 52, 52, 52, 52, 46, 53, 54, 59, 60, 58, 61, 62, 63, 64, 65, 67, 68, 69, 70, 70, 68, 73 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

LINKS

Table of n, a(n) for n=2..73.

MATHEMATICA

Table[Round[(1/Log[2])Log[Denominator[Sum[PrimePi[k]/2^k, {k, 2, x}]]]], {x, 2, 100}]

PROG

(PARI) a(n) = logint(denominator(sum(k=2, n, primepi(k)/2^k)), 2); \\ Michel Marcus, Oct 28 2019

CROSSREFS

Cf. A119523, A127197, A127200.

Sequence in context: A257982 A275705 A217036 * A225844 A006769 A075643

Adjacent sequences:  A127198 A127199 A127200 * A127202 A127203 A127204

KEYWORD

nonn,frac

AUTHOR

Artur Jasinski, Jan 08 2007

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 6 21:24 EDT 2020. Contains 333286 sequences. (Running on oeis4.)