

A246807


Number of nbit 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 base2 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



