818300

Appears in sequences

• Number of permutations of 7 indistinguishable copies of 1..n with exactly 3 adjacent element pairs in decreasing order.at n=2A151657
• Triangle in which the g.f. for row n is [Sum_{k>=0} C(n+k-1,k)^3*x^k]*(1-x)^(3n+1), read by rows of k=0..2n terms.at n=52A181544
• Triangle in which the g.f. for row n is [Sum_{k>=0} C(n+k-1,k)^3*x^k]*(1-x)^(3n+1), read by rows of k=0..2n terms.at n=60A181544
• For 1<=x<=n, 1<=y<=n, write gcd(x,y) = u*x+v*y with u,v minimal; a(n) = n^4*s, where s is the population variance of the values of |v|.at n=20A345690