128598

Appears in sequences

• Numbers k for which A064380(k) = k/2.at n=39A185078
• Number of n-bead necklaces labeled with numbers -4..4 allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.at n=7A209481
• T(n,k) is the number of n-bead necklaces labeled with numbers -k..k allowing reversal, with sum zero and avoiding the patterns z z+1 z+2 and z z-1 z-2.at n=62A209485
• a(n) = Sum_{k=1..n} phi(k)*phi(k+1)*phi(k+2), where phi(k) = A000010(k) is Euler's totient function.at n=38A335131
• Numbers k such that iphi(k) divides k, where iphi is the infinitary Euler phi function (A064380).at n=40A373057