OFFSET
0,3
LINKS
Scott R. Shannon, Image of the terms for n=0..500000.
EXAMPLE
a(9) = 9 as the concatenation of all previous terms is "012345678" which does not include 9, so a(9) = 9.
a(12) = 13 as the concatenation of all previous terms is "01234567891011" which includes "12" as a substring, starting 13 digits from the end of the concatenation.
a(13) = 2 as the concatenation of all previous terms is "0123456789101113" which includes "13" as a substring, starting 2 digits from the end of the concatenation.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Scott R. Shannon, Feb 14 2021
STATUS
approved