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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A086904 Write the primes in binary; a(n) = total number of 0's in those which have an n-bit expansion. 1
1, 1, 2, 7, 13, 35, 71, 147, 298, 622, 1270, 2558, 5257, 10509, 21297, 42852, 86258, 173528, 348187, 699590, 1404936, 2818606, 5657411, 11345622, 22746823 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,3

LINKS

Table of n, a(n) for n=2..26.

EXAMPLE

a(2) = 1: 2 = 10 and 3 = 11, with a total of one 0.

a(3) = 1: 5 = 101, 7 = 111, again with just one 0.

PROG

(PARI) a(n) = {nb = 0; for (i=2^(n-1), 2^n-1, if (isprime(i), nb += n - norml2(binary(i))); ); return (nb); } \\ Michel Marcus, Jun 20 2013

CROSSREFS

Cf. A168156.

Sequence in context: A231478 A079119 A051748 * A291276 A217305 A026555

Adjacent sequences:  A086901 A086902 A086903 * A086905 A086906 A086907

KEYWORD

base,nonn

AUTHOR

Jacob Woolcutt (woolcutt(AT)uiuc.edu), Sep 19 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 18 18:10 EDT 2018. Contains 316323 sequences. (Running on oeis4.)