P548
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Gozinta Chains

ℹ️Published on Sunday, 21st February 2016, 07:00 am; Solved by 696;
Difficulty rating: 35%

A gozinta chainfor $n$ is a sequence $\{1,a,b,\dots,n\}$ where each element properly divides the next.
There are eight gozinta chains for $12$:
$\{1,12\}$, $\{1,2,12\}$, $\{1,2,4,12\}$, $\{1,2,6,12\}$, $\{1,3,12\}$, $\{1,3,6,12\}$, $\{1,4,12\}$ and $\{1,6,12\}$.
Let $g(n)$ be the number of gozinta chains for $n$, so $g(12)=8$.
$g(48)=48$ and $g(120)=132$.

Find the sum of the numbers $n$ not exceeding $10^{16}$ for which $g(n)=n$.



Soluzione

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