790211926076domain: NAppears in sequencesExpansion of c(5x^2)/(1-x*c(5x^2)), where c(x) is the g.f. of A000108.at n=21A128387Number of 6-ary words either empty or beginning with the first character of the alphabet, that can be built by inserting n doublets into the initially empty word.at n=11A194726