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!)
A246807 Number of n-bit numbers that can be written as the concatenation of 0 or more prime numbers (everything written in base 2). 1
1, 0, 2, 2, 5, 8, 15, 33, 59, 126, 246, 494, 978, 1971, 3930, 7845, 15749, 31527, 63349, 126986, 254880, 511468, 1026348, 2060633, 4135808, 8303940, 16669925, 33472231, 67201664 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Here we only consider canonical base-2 expansions (with no leading zeros).  1 is not a prime, and neither is 0.

LINKS

Table of n, a(n) for n=0..28.

EXAMPLE

For n = 5 the 8 solutions counted include the primes {17,19,23,29,31} between 16 and 31, and also the numbers 21 (10.101), 22 (101.10), and 30 (111.10).

CROSSREFS

Cf. A246806.

Sequence in context: A052527 A042982 A006367 * A077902 A005834 A052531

Adjacent sequences:  A246804 A246805 A246806 * A246808 A246809 A246810

KEYWORD

nonn,base,more

AUTHOR

Jeffrey Shallit, Nov 16 2014

EXTENSIONS

More terms from Jeffrey Shallit, Nov 25 2014

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 18:48 EDT 2020. Contains 334854 sequences. (Running on oeis4.)