

A173022


Number of numbers <= n having no isolated ones in their binary representations.


5



1, 1, 1, 2, 2, 2, 3, 4, 4, 4, 4, 4, 5, 5, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 9, 10, 10, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 13, 13, 13, 14, 14, 14, 15, 16, 17, 17, 17, 18, 19, 19, 20, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21, 21
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,4


COMMENTS

a(A144795(n+1)) = a(A144795(n)) + 1;
a(2^n  1)) = A005251(n+1);
A173021(n) <= a(n) <= A173023(n).


LINKS

R. Zumkeller, Table of n, a(n) for n = 0..10000


EXAMPLE

a(20)=#{0,3,6,7,12,14,15}=#{0,11,110,111,1100,1110,1111}=7.


CROSSREFS

Sequence in context: A322210 A228482 A091822 * A060973 A097915 A255072
Adjacent sequences: A173019 A173020 A173021 * A173023 A173024 A173025


KEYWORD

base,nonn


AUTHOR

Reinhard Zumkeller, Feb 07 2010


STATUS

approved



