(-1)-sigma super perfect numbers: (-1)sigma((-1)sigma(x))=2*x, where if x=Product p(i)^r(i) then (-1)sigma(x)=Product (-1+Sum p(i)^s(i), s(i)=1 to r(i)); (-1)sigma(1)=1.
A051153
(-1)-sigma super perfect numbers: (-1)sigma((-1)sigma(x))=2*x, where if x=Product p(i)^r(i) then (-1)sigma(x)=Product (-1+Sum p(i)^s(i), s(i)=1 to r(i)); (-1)sigma(1)=1.
Terms
- a(0) =247a(1) =988a(2) =2808a(3) =10440a(4) =87696a(5) =151200a(6) =191052a(7) =263520a(8) =2630320a(9) =3961980
External references
- oeis: A051153