21003948

Appears in sequences

• Theta series of 12-dimensional Coxeter-Todd lattice K_12.at n=16A004010
• Integer areas A of the integer-sided triangles such that the inradius and the radius of the three excircles are perfect squares.at n=28A233317
• Triangular array read by rows. T(n,k) is the number of labeled posets on [n] of rank at most one with exactly k elements of positive indegree, n >= 0, 0 <= k <= max{0,n-1}.at n=40A369919