Table of Reciprocal Amicable Pairs
| Type | Known | Last update | | Ordinary | 6 7D-35D | 3-Mar-2003 | | Unitary | 3 8D-27D | 3-Mar-2003 | | -1sigma | 0 0D | 3-Mar-2003 | | Unitary phi | 40 1D-17D | 3-Mar-2003 |
| |
click on numbers
Thanks to Hickerson
[Definition]
Reciprocal AP :
1/sigma(a)=1/sigma(b)=1/k*(1/a+1/b)
where if x=product p_i^r_i then sigma(x)=product (sum p_i^s_i , s_i=0 to r_i)
Unitary reciprocal AP :
1/usigma(a)=1/usigma(b)=1/k*(1/a+1/b)
where if x=product p_i^r_i then usigma(x)=product (p_i^r_i+1)
(-1)-sigma reciprocal AP :
1/-1sigma(a)=1/-1sigma(b)=1/k*(1/a+1/b)
where if x=product p_i^r_i then -1sigma(x)=product (-1 + sum p_i^s_i , s_i=1 to r_i)
Unitary phi reciprocal AP :
1/uphi(x)=1/uphi(y)=k*(1/x-1/y)
where if x=product p_i^r_i then uphi(x)=product (p_i^r_i-1)
Note 1 : Reciprocal AP is also represented as sigma(a)=sigma(b)=k*a*b/(a+b).
So, it is one of the Rational APs.
Note 2 : All terms of -1sigma(x) are divisors of x, it is not the sum of divisors but
a difference of divisors of x.
under consstruction