2561439806

Appears in sequences

• Expansion of c(5x^2)/(1-x*c(5x^2)), where c(x) is the g.f. of A000108.at n=17A128387
• Number of n-ary words beginning with the first character of the alphabet, that can be built by inserting nine doublets into the initially empty word.at n=6A194721
• Number 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=9A194726