1443039123

Appears in sequences

• Expansion of c(7*x^2)/(1 - x*c(7*x^2)), where c(x) is the g.f. of A000108.at n=15A132374
• Number of n-ary words beginning with the first character of the alphabet, that can be built by inserting eight doublets into the initially empty word.at n=8A194720
• Number of 8-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=8A194728
• Number of 2n-length words, either empty or beginning with the first character of an n-ary alphabet, that can be built by repeatedly inserting doublets into the initially empty word.at n=8A248828