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A086918
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Numbers with at least three digits such that the absolute differences between successive digits forms a palindrome (when leading zeros are omitted).
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3
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101, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 121, 123, 131, 135, 141, 147, 151, 159, 161, 171, 181, 191, 202, 210, 212, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 232, 234, 242, 246, 252, 258, 262, 272, 282, 292, 303, 313, 321, 323, 330, 331
(list;
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refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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COMMENTS
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All numbers from 0 to 99 trivially have the property, so we require at least three digits.
Question: There seems to be a pattern. Can someone find a formula for index of a given member?
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LINKS
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EXAMPLE
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112 is a member yielding (0)2.
131 and 135 both are members and the palindrome arising in both cases is 22.
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MATHEMATICA
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Select[Range[100, 500], PalindromeQ[FromDigits[Abs[ Differences[ IntegerDigits[ #]]]]]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Nov 14 2019 *)
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CROSSREFS
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KEYWORD
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base,easy,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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