2674440

Appears in sequences

• Symmetrical dissections of an n-gon.at n=26A000063
• Expansion of (sqrt(1-4x^2) - sqrt(1-4x))/(2x).at n=14A000912
• a(n) = T(n, floor(n/2)), where T = Catalan triangle (A008315).at n=26A026008
• a(n) = floor( binomial(n, floor(n/2))/(1 + ceiling(n/2)) ) (interpolates between Catalan numbers).at n=28A028303
• a(n) = ceiling( binomial(n, floor(n/2))/(1 + ceiling(n/2)) ) (interpolates between Catalan numbers).at n=28A028304
• a(n) is the difference between maximal and central squarefree kernel numbers dividing values of {binomial(n,k)} or A001405(n), respectively.at n=26A048682
• Catalan numbers with even index (A000108(2*n), n >= 0): a(n) = binomial(4*n, 2*n)/(2*n+1).at n=7A048990
• GCD of consecutive central binomial coefficients: a(n) = gcd(A001405(n+1), A001405(n)).at n=28A057977
• a(n) = mu(n) * Catalan(n).at n=14A062627
• Smallest number of crossing-free matchings on n points in the plane.at n=27A063549
• 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=27A063786
• Smallest Catalan number (A000108) divisible by n.at n=8A066563
• Smallest Catalan number (A000108) divisible by n.at n=7A066563
• Smallest Catalan number (A000108) divisible by n.at n=14A066563
• Smallest Catalan number (A000108) divisible by n.at n=23A066563
• Smallest Catalan number (A000108) divisible by n.at n=17A066563
• Smallest Catalan number (A000108) divisible by n.at n=29A066563
• Triangle of C(n+1,k)*C(2*n-3*k,n-3*k)/(n+1) by rows.at n=40A073187
• Quotient C[p(n),{p(n)+-1}/2]/p(n), where p(n)=n-th prime.at n=8A075891
• Number of fixed points in range [A014137(n-1)..A014138(n-1)] of permutation A089864.at n=29A089408