661500

Appears in sequences

• Unitary harmonic numbers (those for which the unitary harmonic mean is an integer).at n=38A006086
• a(n) = n^2 * (n+1)^3.at n=14A099762
• Number of ways to place 2 nonattacking amazons (superqueens) on an n X n toroidal board.at n=34A178972
• a(n) = Product_{d|n, d<n} A019565(d).at n=23A293214
• a(n) = Product_{d|n, d<n} A260443(d).at n=23A293216
• a(n) = Product_{d|n, d<n} A019565(A193231(d)).at n=29A293231
• Consider coefficients U(m,L,k) defined by the identity Sum_{k=1..L} Sum_{j=0..m} A302971(m,j)/A304042(m,j) * k^j * (T-k)^j = Sum_{k=0..m} (-1)^(m-k) * U(m,L,k) * T^k that holds for all positive integers L,m,T. This sequence gives 3-column table read by rows, where the n-th row lists coefficients U(2,n,k) for k = 0, 1, 2; n >= 1.at n=40A316349
• Expansion of 60*x*(1 + 4*x + x^2) / (1 - x)^5.at n=13A316458
• a(n) is the smallest number k for which k and the arithmetic derivative k' (A003415) have exactly n triangular divisors (A000217).at n=15A357842