68381

Appears in sequences

• Numbers n such that sigma(phi(n))/sigma(n) = 3.at n=13A067383
• a(n) = (2*n+1)*(2*n+3)*(2*n+5)/3.at n=28A162540
• Number of Grassmannian permutations of size n that avoid a pattern, sigma, where sigma is a pattern of size 6 with exactly one descent.at n=25A362193