247285

Appears in sequences

• Number of paraffins (see Losanitsch reference for precise definition).at n=36A006010
• Numbers k such that sigma(phi(k))-phi(sigma(k)) is nonzero and is divisible by (k-1), that is A065395(k)/(k-1) = (phi(sigma(k))-sigma(phi(k)))/(k-1) is a nonzero integer.at n=12A092585
• The sum of the numbers of the central diamond of the multiplication table [1..k] X [1..k] for k=2*n-1.at n=18A357042