240480

Appears in sequences

• Irregular array, read by rows: T(n,k) is the number of labeled acyclic digraphs with n nodes and k arcs (n >= 0, 0 <= k <= n*(n-1)/2).at n=32A081064
• Number of consistent sets of 6 irreflexive binary order relationships over n objects.at n=2A147860
• Unchanging value maps: number of 2 X n binary arrays indicating the locations of corresponding elements unequal to no horizontal or antidiagonal neighbor in a random 0..2 2 X n array.at n=11A219422
• Number of lines through at least two points of a centered hexagonal grid of size n.at n=18A241220
• a(n) = [x^(2*n)] Product_{k=0..n-1} (1 + k*x)^3.at n=5A384026