3-perfect (triply perfect, tri-perfect, triperfect or sous-double) numbers: numbers such that the sum of the divisors of n is 3n.
A005820
3-perfect (triply perfect, tri-perfect, triperfect or sous-double) numbers: numbers such that the sum of the divisors of n is 3n.
Terms
- a(0) =120a(1) =672a(2) =523776a(3) =459818240a(4) =1476304896a(5) =51001180160
External references
- oeis: A005820