372945

Appears in sequences

• Odd n such that 2*phi(n) < n, but there does not exist an even k < n with phi(k) = phi(n).at n=21A118700
• a(n) = n^2 * (4*n^2 - 1) / 3.at n=23A187756
• Expansion of Sum_{k>0} x^k / (1 - k * x^k)^(k+1).at n=25A360794