116116

Appears in sequences

• Number of rooted toroidal maps with 2 faces, n vertices and no isthmuses.at n=10A006469
• Numbers k such that 163*2^k+1 is prime.at n=47A032458
• Numbers k such that usigma(k) = phi(k)*omega(k), where omega(k) is the number of distinct prime divisors of k.at n=31A063795
• Numbers k such that phi(k) = sigma(core(k)) where phi(k) is the Euler totient function, sigma(k) the sum of divisors of k and core(k) the squarefree part of k (the smallest integer such that k*core(k) is a square).at n=14A069552
• Numbers n such that sigma(n) = 7*phi(n).at n=16A136540
• 4n concatenated with itself.at n=28A248365
• G.f. A(x) satisfies A(x) = 1 / (1 - x * A(x^4)).at n=39A367794
• Numbers k such that sigma(k) = psi(k) + phi(k).at n=22A389478