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%I #24 Mar 06 2026 08:07:08
%S 0,1,2,3,4,5,6,7,8,9,101,202,212,303,313,323,404,414,424,434,505,515,
%T 525,535,545,606,616,626,636,646,656,707,717,727,737,747,757,767,808,
%U 818,828,838,848,858,868,878,909,919,929,939,949,959,969,979,989,11011,12021,13031,14041,15051
%N Palindromes that have only one smallest digit (strict minimum).
%C All terms have an odd number of digits. The sequence is infinite.
%C Differs first from A266139 in not having 12121. - _R. J. Mathar_, Mar 06 2026
%H Michael S. Branicky, <a href="/A393807/b393807.txt">Table of n, a(n) for n = 1..10000</a>
%t Select[Range[0,15200],PalindromeQ[#] &&Count[digits=IntegerDigits[#], Min[digits]]==1 &] (* _Stefano Spezia_, Feb 28 2026 *)
%o (Python)
%o from itertools import count, islice, product
%o def agen():
%o yield from range(10)
%o for digs in count(3, step=2):
%o for first in "123456789":
%o for left in product("123456789", repeat=(digs-3)//2):
%o left = "".join(left)
%o mn = int(min(first+left))
%o for mid in "".join(map(str, range(0, mn))):
%o yield int(first + left + mid + left[::-1] + first)
%o print(list(islice(agen(), 60))) # _Michael S. Branicky_, Feb 28 2026
%Y Supersequence of A393015.
%Y Cf. A002113, A110785, A134970.
%K nonn,base
%O 1,3
%A _Alexander Yutkin_, Feb 28 2026