-7750

Appears in sequences

• Square array A(n,k), n >= 1, k >= 1, read by antidiagonals downwards, where A(n,k) = -(1/n) * Sum_{d|n} phi(n/d) * (-k)^d.at n=60A382993
• Square array A(n,k), n >= 1, k >= 1, read by antidiagonals downwards, where A(n,k) = Sum_{d|n} phi(n/d) * (-k)^(d-1).at n=60A382995
• a(n) = Sum_{d|n} phi(n/d) * (-n)^(d-1).at n=5A382998