1584000

Appears in sequences

• Commuting elements: number of ordered pairs g, h in the group GL(2,Z_n) such that gh = hg.at n=10A070943
• Number of defective (binary) heaps on n elements where two ancestor-successor pairs do not have the correct order.at n=12A324063
• Consider the e.g.f. B(x,y) = Sum_{n>=0} Sum_{k=0..floor(n/2)} T(n,k) * x^(2*n-2*k) * y^(2*k) / (2*n)! and related functions A(x,y) and C(x,y), as defined in the Formula section. Sequence gives the triangular array of coefficients T(n,k) (n>=0, 0<=k<=floor(n/2)) of B(x,y).at n=14A326798
• Nonsquare integers >= 2 for which the square of its largest prime factor equals the sum of the squares of its other prime factors, with multiplicity.at n=23A391874