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Multiamicable Numbers

Two integers $n$ and $m<n$ are $(\alpha, \beta)$-multiamicable if

\begin{displaymath}
\sigma(m)-m=\alpha n
\end{displaymath}

and

\begin{displaymath}
\sigma(n)-n=\beta m,
\end{displaymath}

where $\sigma(n)$ is the Divisor Function and $\alpha,\beta$ are Positive integers. If $\alpha=\beta=1$, $(m,n)$ is an Amicable Pair.


$m$ cannot have just one distinct prime factor, and if it has precisely two prime factors, then $\alpha=1$ and $m$ is Even. Small multiamicable numbers for small $\alpha,\beta$ are given by Cohen et al. (1995). Several of these numbers are reproduced in the below table.

$\alpha$ $\beta$ $m$ $n$
1 6 76455288 183102192
1 7 52920 152280
1 7 16225560 40580280
1 7 90863136 227249568
1 7 16225560 40580280
1 7 70821324288 177124806144
1 7 199615613902848 499240550375424

See also Amicable Pair, Divisor Function


References

Cohen, G. L; Gretton, S.; and Hagis, P. Jr. ``Multiamicable Numbers.'' Math. Comput. 64, 1743-1753, 1995.




© 1996-9 Eric W. Weisstein
1999-05-26