2434755domain: NAppears in sequencesNumbers k such that 3^k == -1 (mod k-1).at n=31A055686a(n) = number of n-lettered words in the alphabet {1, 2, 3} with as many occurrences of the substring (consecutive subword) [1, 2, 1] as of [1, 3, 1].at n=14A211297