67117128

Appears in sequences

• a(n) = Sum_{d|n} phi(d)*2^(n/d).at n=26A053635
• a(n) = Sum_{d|n} (2^d + 2*(-1)^d)*phi(n/d).at n=25A306896
• a(n) = Sum_{k=1..n} n^(n/gcd(n, k)).at n=7A332620