742900

Appears in sequences

• Symmetrical dissections of an n-gon.at n=24A000063
• Catalan numbers with odd index: a(n) = binomial(4*n+2, 2*n+1)/(2*n+2).at n=6A024492
• a(n) = T(n, floor(n/2)), where T = Catalan triangle (A008315).at n=24A026008
• a(n) = floor( binomial(n, floor(n/2))/(1 + ceiling(n/2)) ) (interpolates between Catalan numbers).at n=26A028303
• a(n) = ceiling( binomial(n, floor(n/2))/(1 + ceiling(n/2)) ) (interpolates between Catalan numbers).at n=26A028304
• Central binomial coefficient A001405(n) divided by its characteristic cube divisor A056201(n).at n=26A056202
• GCD of consecutive central binomial coefficients: a(n) = gcd(A001405(n+1), A001405(n)).at n=26A057977
• Smallest number of crossing-free matchings on n points in the plane.at n=25A063549
• 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=25A063786
• 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=24A063786
• Smallest Catalan number (A000108) divisible by n.at n=19A066563
• Smallest Catalan number (A000108) divisible by n.at n=24A066563
• a(1) = 1. a(n) = n*a(n-1) if gcd(n,a(n-1)) = 1, a(n-1)/n if n divides a(n-1), otherwise a(n) = a(n-1).at n=25A068629
• Triangle of C(n+1,k)*C(2*n-3*k,n-3*k)/(n+1) by rows.at n=35A073187
• Number of fixed points in range [A014137(n-1)..A014138(n-1)] of permutation A089864.at n=27A089408
• Number of fixed points in range [A014137(n-1)..A014138(n-1)] of permutation A069772.at n=27A089849
• Largest gcd of two distinct numbers on row n of Pascal's triangle.at n=23A092394
• 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=13A092935
• Numerators of even raw moments in the distribution of line lengths for lines picked at random in the unit disk.at n=12A093526
• Expansion of 1 + 2x/(1 + sqrt(1 - 4x^2)).at n=27A097331