137885

Appears in sequences

• Odd integers m such that phi(m) | sigma(m).at n=32A015715
• Numbers n such that sigma(n) = 2*phi(n).at n=9A062699
• Numbers k such that sigma(k) = phi(k*bigomega(k)).at n=29A068400
• Numbers n such that sigma(n) = phi(3n).at n=17A074891
• Numbers k such that k, 2*k and 4*k are balanced numbers (A020492).at n=23A076376
• Balanced numbers k such that k mod 12 = 5.at n=0A110598
• Alternating sum of the Fibonacci numbers multiplied by their (combinatorial) indices.at n=20A120940
• Numbers k such that gcd(sigma(k), phi(k)) (A009223) attains record values.at n=34A222711
• Numbers n such that psi(n) = 2*phi(n).at n=41A292390
• a(n) is the first positive number k such that k is alternately a quadratic residue and nonresidue modulo the first n primes, but not the n+1'th.at n=15A377380