259289580

Appears in sequences

• a(n) = (1/(4n-1))*C(4n,2n).at n=9A024491
• Dirichlet convolution of Catalan numbers (1,2,5,14...) with themselves.at n=16A034717
• Third diagonal of array in A059347.at n=33A059348
• Expansion of (1 + x*C)*C, where C = (1 - (1 - 4*x)^(1/2))/(2*x) is the g.f. for Catalan numbers, A000108.at n=17A068875
• Number of fixed points in range [A014137(n-1)..A014138(n-1)] of permutation A089864.at n=36A089408
• Self-convolution of repeated Catalan numbers.at n=33A104722
• The number of boundary twigs for complete binary twigs. A twig is a vertex with one edge on the boundary and only one other descendant.at n=16A228403
• a(n) = A241477(n, n).at n=36A241543
• Number of rooted asymmetrical polyenoids of type U_n* having n edges.at n=17A262543
• a(-1)=-1; a(n) = 2*A000108(n) for n >= 0.at n=18A284016
• For any n > 0, let b_n(n+1) = 1, and for k = 1..n, if k divides b_n(k+1) then b_n(k) = b_n(k+1) / k otherwise b_n(k) = b_n(k+1) * k; a(n) = b_n(1).at n=33A374317