

A055723


Number of lucky numbers (A000959) <= 10^n.


0



1, 4, 23, 153, 1118, 8772, 71918, 609237, 5286238, 46697909, 418348044, 3790060378, 34652117969, 319239995375, 2960006060823, 27596305747873
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,2


COMMENTS

As the two links show, lucky numbers possess a number of characteristics that are similar to those of the primes. This stems from the fact that both are the result of a sieving process. See A006880.


LINKS

Table of n, a(n) for n=0..15.
W. Schneider, Lucky Numbers
Eric Weisstein's World of Mathematics, Lucky Numbers


MATHEMATICA

lst = Range[1, 10^6, 2]; i = 2; While[ i <= (len = Length@lst) && (k = lst[[i]]) <= len, lst = Drop[lst, {k, len, k}]; i++ ]; Table[ Length@ Select[t, #<=10^n &], {n, 8}] (* Robert G. Wilson v *)


CROSSREFS

Cf. A000959, A006880.
Sequence in context: A193113 A192730 A246813 * A271469 A007297 A263843
Adjacent sequences: A055720 A055721 A055722 * A055724 A055725 A055726


KEYWORD

base,more,nonn


AUTHOR

Robert G. Wilson v, Jun 09 2000


EXTENSIONS

a(8),a(9) were calculated by Walter Schneider (wschnei(AT)tonline.de).
a(10) from Robert G. Wilson v, Oct 16 2010
a(11)a(15) from Hiroaki Yamanouchi, May 07 2015


STATUS

approved



