OFFSET
1,1
COMMENTS
The sequence is infinite: a(n) always exists.
For computer programs and examples see A224752.
Appears to be (1/4) * #{ k < 10^n | 2k has no digit 0 }, at least up to n = 8. Has anyone a simple explanation for this? - M. F. Hasler, Oct 10 2019
REFERENCES
Eric Angelini, Postings to the Sequence Fans Mailing List, Apr 13 2013
LINKS
Eric Angelini, Magic Sums
E. Angelini, Magic Sums [Cached copy, with permission]
PROG
CROSSREFS
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, Apr 21 2013
STATUS
approved