-1558

Appears in sequences

• a(n) = A006496(n)/2.at n=10A045873
• Difference between sums of quadratic residues and non-residues modulo n (residues are not necessarily coprime to n).at n=75A255644
• Dirichlet inverse of A341529, where A341529(n) = sigma(n) * A003961(n), and A003961 is fully multiplicative with a(prime(i)) = prime(i+1).at n=36A378229