883634026

Appears in sequences

• a(n) = C_n / 2 if n is even or ( C_n + C_((n-1)/2) ) / 2 if n is odd, where C = Catalan numbers (A000108).at n=18A007595
• Number of plane trees with even number of leaves.at n=18A071688
• Number of cycles in range [A014137(n-1)..A014138(n-1)] of permutation A089864.at n=19A089402
• Number of cycles in range [A014137(n-1)..A014138(n-1)] of permutation A082335/A082336.at n=20A089421
• Number of cycles in range [A014137(n-1)..A014138(n-1)] of permutation A069772.at n=19A089880