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A332970
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Colombian palindromes.
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0
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1, 3, 5, 7, 9, 121, 222, 323, 424, 525, 626, 727, 828, 929, 1111, 2112, 3113, 4114, 5115, 6116, 7117, 8118, 9119, 10401, 11211, 12921, 13731, 14541, 15351, 16161, 18881, 19691, 20402, 21212, 22922, 23732, 24542, 25352, 26162, 28882, 29692, 30403, 31213, 32923
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OFFSET
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1,2
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COMMENTS
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Palindromes that are not the sum of an integer and of the individual digits of this integer (see Wikipedia link).
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LINKS
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EXAMPLE
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323 is a palindrome that cannot be written as the sum of any other natural number k and the digits of k, hence 323 that is Colombian number in base 10 is a term.
333 is a palindrome but 333 = 324 + 3 + 2 + 4, hence 333 that is not a self number in base 10 is not a term.
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MATHEMATICA
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n = 33000; Select[Complement[Range[n], Union @ Table[Plus @@ IntegerDigits[k] + k, {k, 1, n}]], PalindromeQ] (* Amiram Eldar, Mar 04 2020 *)
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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