The exceptional three-antipalindrome conjecture

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An antipalindrome is a natural number whose canonical base-22 expansion equals the complement of its reversal. Let

E={8,18,28,130,134,138,148,158,176,318,530,538,548,576,644,1300,2170,2202,2212,2228,2230,2248,8706,8938,8948,34970,35082}.E=\{8,18,28,130,134,138,148,158,176,318,530,538,548,576,644,1300,2170,2202,2212,2228,2230,2248,8706,8938,8948,34970,35082\}.

Exceptional three-antipalindrome conjecture. Every even natural number outside EE is the sum of at most 33 antipalindromes.

The claim is presented as a numerical conjecture refining the preceding four-antipalindrome bound. The listed exceptions are the only exceptions asserted by the source, and no proof or resolution is provided.

References

Primary source

Aayush Rajasekaran, Jeffrey Shallit and Tim Smith, “Sums of Palindromes: an Approach via Automata”, arXiv:1706.10206 (2017).

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