104006

Appears in sequences

• Number of dissections of an n-gon, rooted at an exterior edge, asymmetric with respect to that edge.at n=12A000150
• Expansion of (1-4*x)^(7/2).at n=16A002423
• 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=11A007595
• Expansion of Product_{k>=1} (1 - x^k)^17.at n=25A010823
• Expansion of 1/(1-4*x)^(17/2).at n=4A020928
• a(n) = floor( binomial(n, floor(n/2))/(1 + ceiling(n/2)) ) (interpolates between Catalan numbers).at n=23A028303
• a(n) = ceiling( binomial(n, floor(n/2))/(1 + ceiling(n/2)) ) (interpolates between Catalan numbers).at n=23A028304
• Number of aperiodic necklaces of n beads of 2 colors, 11 of them black.at n=12A032169
• Number of necklaces with 11 black beads and n-11 white beads.at n=13A032196
• Expansion of (1+x*C^4)*C^2, where C = (1-(1-4*x)^(1/2))/(2*x) is g.f. for Catalan numbers, A000108.at n=9A032952
• Squarefree part of n!: n! divided by its largest square divisor.at n=25A055204
• Squarefree part of the n-th central binomial coefficient.at n=25A056058
• a(n) = ((2n+1) + (2n-1) - 1)!/((2n+1)!*(2n-1)!).at n=6A065097
• Squarefree part of C(2n,n), the central binomial numbers: the smallest number such that a(n)*C(2n,n) is a square.at n=13A069113
• Number of plane trees with n edges and having an odd number of leaves.at n=11A071684
• Number of plane trees with even number of leaves.at n=11A071688
• 3-apexes of omega: numbers k such that omega(k-3) < omega(k-2) < omega(k-1) < omega(k) > omega(k+1) > omega(k+2) > omega(k+3), where omega(m) = the number of distinct prime factors of m.at n=0A076761
• a(n) is the smallest integer of the form a*b*c.../p*q*r..., where the numerator and the denominator contain n numbers each and a,b,c,...p,q,r... are all the integers from 1 to 2n.at n=12A085057
• Sixth column of triangle A028364.at n=6A116869
• Catalan numbers halved and rounded to the next integer.at n=12A130380