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A255724
List of numbers such that no number, nor its reverse, is in the concatenation of all previous terms.
0
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 20, 22, 24, 25, 26, 27, 29, 30, 33, 35, 36, 37, 38, 40, 44, 46, 47, 49, 50, 55, 57, 58, 60, 66, 69, 70, 77, 80, 88, 90, 99, 100, 102, 103, 104, 105, 106, 107, 108, 109, 112, 114, 115, 116, 117, 118, 122
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
Cf. A048991.
Sequence in context: A343268 A107909 A357758 * A285100 A368007 A360553
KEYWORD
nonn,base,easy
AUTHOR
Phil Carmody, Mar 19 2015
EXTENSIONS
More terms from Jinyuan Wang, Aug 23 2021
STATUS
approved