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A349805
a(n) = A261138(n)/11.
2
1, 111, 11211, 1122211, 112232211, 11223332211, 1122334332211, 112233444332211, 11223344544332211, 112233444636544332211, 1122334446373736544332211, 11223344463737473736544332211, 112233444637374666473736544332211, 1122334446373746649466473736544332211, 11223344463737466492319466473736544332211
OFFSET
1,2
MAPLE
a:= n-> (s-> parse(cat(s, seq(s[-i], i=1..length(s))))/11)(cat("", $1..n)):
seq(a(n), n=1..14); # Alois P. Heinz, Dec 01 2021
PROG
(Python)
def A349805(n): return int((lambda x: x+x[::-1])(''.join(str(d) for d in range(1, n+1))))//11 # Chai Wah Wu, Dec 01 2021
CROSSREFS
Cf. A261138.
A109242 has the same initial terms.
Sequence in context: A111864 A098034 A109242 * A165155 A078270 A298677
KEYWORD
nonn,base
AUTHOR
N. J. A. Sloane, Dec 01 2021
EXTENSIONS
More than the usual number of terms are shown in order to distinguish this from several similar sequences.
STATUS
approved