3183156domain: NAppears in sequencesExpansion of c(5x^2)/(1-x*c(5x^2)), where c(x) is the g.f. of A000108.at n=12A128387G.f.: 5/(2 + 3*sqrt(1-20*x)).at n=6A130977Number of length 2n n-ary words that can be built by repeatedly inserting doublets into the initially empty word.at n=6A294491