79521

Appears in sequences

• Numbers k such that lcm(1,2,3,...,k)/17 equals the denominator of the k-th harmonic number H(k).at n=31A112820
• Twin prime products minus 2.at n=18A124659
• Compound filter: a(n) = P(sigma(n), sigma(2n)), where P(n,k) is sequence A000027 used as a pairing function, and sigma is the sum of divisors (A000203).at n=53A286359