Lexicographically earliest sequence of distinct terms such that the concatenation of three successive terms form a palindrome using the alphabet {1, 2}.

A355404

Lexicographically earliest sequence of distinct terms such that the concatenation of three successive terms form a palindrome using the alphabet {1, 2}.

Terms

    a(0) =1a(1) =2a(2) =21a(3) =22a(4) =12a(5) =122a(6) =121a(7) =221a(8) =22121a(9) =22122a(10) =12122a(11) =12122122a(12) =12122121a(13) =22122121

External references