4638348

Appears in sequences

• Number of 8-ary trees with n vertices.at n=7A007556
• Array read by antidiagonals: T(r,n) = number of two-stack sortable r-permutations.at n=52A093346
• a(n) = binomial(n*(n+1),n)/(n^2+1).at n=7A135862
• Generalized or s-Catalan numbers.at n=35A137211
• a(0) = 1; a(n) = Sum_{k=0..floor((n-1)/7)} a(7*k) * a(n-1-7*k).at n=49A386396