28552

Appears in sequences

• Product of prime(n+1)-1 and prime(n)-1.at n=38A083553
• a(n) = A130179(n)/81.at n=25A130085
• Numbers n such that sigma(phi(n)) = sigma(n) - phi(n).at n=6A230371
• Number of (2+1) X (n+1) 0..1 arrays with every 2 X 2 subblock ne-sw antidiagonal difference nondecreasing horizontally and nw+se diagonal sum nondecreasing vertically.at n=35A258555
• a(n) = Sum_{k=1..n-1} k^8*sigma(k)*sigma(n-k).at n=3A259696
• Triangle read by rows: T(m,n) (m >= n >= 1) = number of edges formed by drawing the line segments connecting any two of the (m+1) X (n+1) lattice points in an m X n grid of squares and extending them to the boundary of the grid.at n=14A333283