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A061917
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Either a palindrome or becomes a palindrome if trailing 0's are omitted.
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17
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0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 20, 22, 30, 33, 40, 44, 50, 55, 60, 66, 70, 77, 80, 88, 90, 99, 100, 101, 110, 111, 121, 131, 141, 151, 161, 171, 181, 191, 200, 202, 212, 220, 222, 232, 242, 252, 262, 272, 282, 292, 300, 303, 313, 323, 330, 333, 343, 353, 363, 373, 383, 393, 400, 404
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,3
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COMMENTS
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Numbers that are palindromes when written with a suitable number of leading zeros. - Jeppe Stig Nielsen, Jan 17 2022
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LINKS
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FORMULA
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MATHEMATICA
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PaleQ[n_Integer, base_Integer] := Module[{idn, trim = n/base^IntegerExponent[n, base]}, idn = IntegerDigits[trim, base]; idn == Reverse[idn]]; Select[Range[0, 500], PaleQ[#, 10] &] (* Lei Zhou, Dec 13 2013 *)
Join[{0}, Select[Range[500], PalindromeQ[FromDigits[Drop[IntegerDigits[#], -IntegerExponent[#, 10]]]]&]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 27 2017 *)
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PROG
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(Haskell)
a061917 n = a061917_list !! (n-1)
a061917_list = filter chi [0..] where
chi x = zs == reverse zs where
zs = dropWhile (== '0') $ reverse $ show x
(PARI) isOK(k)=k==0||fromdigits(Vecrev(digits(k)))==k/10^valuation(k, 10) \\ Jeppe Stig Nielsen, Jan 17 2022
(Python)
def ispal(s): return s == s[::-1]
def ok(n): s = str(n); return ispal(s) or ispal(s.rstrip('0'))
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CROSSREFS
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KEYWORD
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nonn,base,easy,nice
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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