3801600

Appears in sequences

• Number of nonnegative integer 3 X 3 matrices with sum of elements equal to n, under action of dihedral group of the square D_4.at n=28A054343
• Number of permutations of {1,2,...,n} that result in a binary search tree with the minimum possible height.at n=12A076615
• a(n) = 8*(n-1)*(n-2)*(n-3)*(6*n^2-37*n+60).at n=11A134241
• Greatest common divisor of (x^m+y^m+(x+y)^m) - (z^m+t^m+(z+t)^m) over all x,y,z,t such that x^2 + xy + y^2 = z^2 + zt + t^2 and m=2n.at n=3A238595
• Number T(n,k) of permutations of {1,2,...,n} that result in a binary search tree of height k; triangle T(n,k), k>=0, k<=n<=2^k-1, read by columns.at n=17A244108
• Numbers n such that lcm(sigma(n), n) = tau(n) * sigma(n) where sigma(k) = the sum of the divisors of k (A000203) and tau(k) = the number of divisors of k (A000005).at n=10A306655
• Number of defective (binary) heaps on n elements where three ancestor-successor pairs do not have the correct order.at n=12A324064