login
A291555
Number of even numbers less than 10^n that contain their greatest odd factor as a substring.
1
0, 1, 4, 15, 40, 57, 76, 108, 146, 194, 258, 336, 447, 544, 663, 807, 970, 1132, 1333, 1567
OFFSET
1,3
COMMENTS
The number of terms of A291460 less than 10^n.
2^10*x = 1024*x contains x for all x from 1 to 41. Therefore, most of the terms in A291460 less than 10^5 are of the form 1024*x for odd x from 1 to 41.
EXAMPLE
There are 4 numbers in A291460 less than 10^3 = 1000 (16, 128, 384, 512). Therefore, a(3) = 4.
CROSSREFS
Sequence in context: A014629 A062486 A193226 * A336995 A053698 A162867
KEYWORD
nonn,base,more
AUTHOR
EXTENSIONS
a(14)-a(20) from Giovanni Resta, Aug 31 2017
STATUS
approved