35357670

Appears in sequences

• Symmetrical dissections of an n-gon.at n=30A000063
• Symmetrical dissections of an n-gon.at n=29A000063
• Expansion of (sqrt(1-4x^2) - sqrt(1-4x))/(2x).at n=16A000912
• Incorrect version of A035010.at n=14A019275
• a(n) = T(n, floor(n/2)), where T = Catalan triangle (A008315).at n=30A026008
• a(n) = floor( binomial(n, floor(n/2))/(1 + ceiling(n/2)) ) (interpolates between Catalan numbers).at n=32A028303
• a(n) = ceiling( binomial(n, floor(n/2))/(1 + ceiling(n/2)) ) (interpolates between Catalan numbers).at n=32A028304
• Number of prime binary rooted trees with n external nodes.at n=15A035010
• Catalan numbers with even index (A000108(2*n), n >= 0): a(n) = binomial(4*n, 2*n)/(2*n+1).at n=8A048990
• GCD of consecutive central binomial coefficients: a(n) = gcd(A001405(n+1), A001405(n)).at n=32A057977
• Smallest number of crossing-free matchings on n points in the plane.at n=31A063549
• G.f.: A(x) = (x-2*x^2-2*x^3-(1+x)*sqrt(1-4*x^2)+sqrt(1-4*x^6))/(2*x^2).at n=30A063786
• G.f.: A(x) = (x-2*x^2-2*x^3-(1+x)*sqrt(1-4*x^2)+sqrt(1-4*x^6))/(2*x^2).at n=31A063786
• Smallest Catalan number (A000108) divisible by n.at n=30A066563
• Number of fixed points in range [A014137(n-1)..A014138(n-1)] of permutation A089864.at n=33A089408
• Number of fixed points in range [A014137(n-1)..A014138(n-1)] of permutation A069772.at n=33A089849
• Carlitz-Riordan q-Catalan numbers (recurrence version) for q = -1.at n=33A090192
• a(1) = 1; a(n) = floor {(n+1)(n+2)(n+3)...(n+k)}/{(n-1)(n-2)(n-3)...(n-k)} for the least value of k.at n=16A092935
• Expansion of 1 + 2x/(1 + sqrt(1 - 4x^2)).at n=33A097331
• An inverse Chebyshev transform of 1-x.at n=32A099363