102656

Appears in sequences

• Numbers k such that the product of Euler phi of the 2 consecutive integers {k,k+1} is a 4th power: if sqrt(sqrt(phi(k)*phi(k+1))) is an integer, then k is here.at n=17A082788
• Nodes of tree generated as follows: (1,2) is an edge, and if (x,y) is an edge, then (y,x*y) and (y,x^2 + y^2) are edges.at n=44A228939
• G.f.: Sum_{n>=0} exp(-n * 2^n * x) * [ Sum_{k>=1} k^n * 2^(n*k) * x^k / k! ]^n.at n=4A277036
• Numbers m such that phi(m)*tau(m) is a square but phi(m)/tau(m) is not the square of an integer.at n=33A341940