191216

Appears in sequences

• Expansion of (1+x*C^4)*C^3, where C = (1-(1-4*x)^(1/2))/(2*x) is g.f. for Catalan numbers, A000108.at n=9A071264
• Concatenation of first 3 digits and last 3 digits of n-th perfect number.at n=9A138877
• Number of certain noncrossing set partitions.at n=10A280891
• a(n) is the number of squares of side length greater than 1 having vertices at the points of an n X n grid of dots.at n=38A328152
• Lexicographically earliest sequence of distinct positive integers with no finite subset summing to a Catalan number (A000108).at n=30A353983