I downloaded the latest sequin executable on NCBI (ftp://ftp.ncbi.nih.gov/sequin/), but I got the following error when I tried to run it on Ubuntu 16.04:

 
$./sequin 
./sequin: error while loading shared libraries: libXp.so.6: cannot open shared object file: No such file or directory

After searching solutions online, I finally solved this problem by these commands:

 
sudo vim /etc/apt/sources.list
# append this line to sources list: deb http://security.ubuntu.com/ubuntu precise-security main
sudo apt update
sudo apt install libxp6