273000

Appears in sequences

• Number of rooted toroidal maps with 2 faces, n vertices and no isthmuses.at n=12A006469
• Numbers k such that the set of prime divisors of k is equal to the set of prime divisors of sigma(k).at n=28A027598
• Twin prime pair averages n such that 3*n and 9*n are also averages of twin prime pairs.at n=2A132992
• Numbers which are the area of exactly three Pythagorean triangles.at n=25A177021
• Numbers with prime factorization pqrs^3t^3.at n=14A190385
• a(n) = A203482(n) / A000178(n).at n=3A203510
• Numbers k such that the squarefree kernel of sigma(k) is equal to the squarefree kernel of 2*k.at n=30A332208
• a(n) is the smallest number k >= 1 with exactly n divisors d, for which sigma(k) is divisible by d*sigma(d).at n=30A344103
• Smallest m such that A356428(m) = n, or -1 if there is no such m.at n=7A356429
• E.g.f. satisfies A(x) = 1/(1 - x * A(x))^(x * A(x)^3).at n=7A356787