OFFSET
0,11
EXAMPLE
The digits of 13 can form 1, 3, 13 and 31. The digits of 201 can form 0, 1, 2, 10, 12, 20, 21, 102, 120, 210 and 201. Thus a(13) = 4, a(201) = 11.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Asher Auel, May 05 2001
STATUS
approved