OFFSET
1,3
EXAMPLE
a(n) = n-1 for 2 <= n <= 13 as a(1) = 0 and no choice for a(n) equals the concatenation of one or more previous terms, so a(n) = a(n-1) + 1 = n-1.
a(14) = 11 as a(13) = 12, and the value '12' is the concatenation of a(2) = 1 and a(3) = 2, and a(2) is eleven terms back from a(13).
a(15) = 2 as a(14) = 11, and the value '11' is a(12), which is two terms back from a(14).
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Scott R. Shannon, Mar 16 2020
STATUS
approved