OFFSET
1,2
EXAMPLE
After listing 1..11, 12 is not listed as "12" is found in the concatenated earlier terms. After continuing with 13..18, 19 is not listed as "91" is likewise found.
PROG
(Perl) $s=""; $_=0; do{$_++; if(index($s, $_)<0 && index($s, reverse)<0){print("$_ "); $s.=$_}}while(1);
(PARI) lista(nn) = my(d, v=[]); for(n=1, nn, for(i=0, #v-#d=digits(n), (v[i+1..i+#d]==d || v[i+1..i+#d]==Vecrev(d)) && next(2)); print1(n, ", "); v=concat(v, d)) \\ Jinyuan Wang, Aug 23 2021
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Phil Carmody, Mar 19 2015
EXTENSIONS
More terms from Jinyuan Wang, Aug 23 2021
STATUS
approved