104704

Appears in sequences

• a(n) = Sum_{1 <= x, y <= n} lcm(x, y).at n=26A064951
• Triangle read by rows, coefficients of the polynomials P(k, x) = (1/2) Sum_{p=0..k-1} Stirling2(k, p+1)*x^p*(1-4*x)^(k-1-p)*(2*p+2)!/(p+1)!.at n=34A142963
• Number of length-4 0..n arrays with no repeated value differing from the previous repeated value by more than one.at n=16A269584
• Start with a single cell at coordinates (0, 0, 0), then iteratively subdivide the grid into 3 X 3 X 3 cells and remove the cells whose sum of modulo 2 coordinates is 2 or 3; a(n) is the number of cells after n iterations.at n=4A285393
• Numbers equal to the sum of their aliquot parts, each of them decreased by 6.at n=0A304283
• a(n) = 2^(n-3)*(3*binomial(n,4) + 4*binomial(n,2) + 8).at n=10A383868