2910712035domain: NAppears in sequencesExpansion of x/(1 - 7*x - 2*x^2).at n=12A015555Number of n-length words w over ternary alphabet {1,2,3} such that for every prefix z of w we have 0<=#(z,1)-#(z,2)<=2 and 0<=#(z,2)-#(z,3)<=2 and #(z,x) gives the number of occurrences of letter x in z.at n=34A225879