109476

Appears in sequences

• Number of permutations of 2 copies of 1..n avoiding adjacent step pattern up, up, down, up, down, down.at n=4A177591
• Total number of words beginning with the first letter of an n-ary alphabet in all multisets of nonempty words with a total of n letters.at n=6A292873
• E.g.f.: exp( exp(x) * (1 + x + x^2 / 2 + x^3 / 6) - 1 ).at n=7A347666