pamstereogram: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/pamstereogram - from package: netpbm-progs

You may install the required package with command yum install {package}
Error in other languages:
pamstereogram: bevel nie gevind nie
pamstereogram: comandă negăsită
pamstereogram: comando não encontrado
pamstereogram: commande introuvable
pamstereogram: command not found
pamstereogram: käsku ei ole
pamstereogram: không tìm thấy lệnh
pamstereogram: komanda nerasta
pamstereogram: Kommando nicht gefunden.
pamstereogram: kommandot finns inte
pamstereogram: komut yok
pamstereogram: nie znaleziono polecenia
pamstereogram: níor aimsíodh an t-ordú
pamstereogram: no se encontró la orden
pamstereogram: no s'ha trobat l'ordre
pamstereogram: opdracht niet gevonden
pamstereogram: parancs nem található
pamstereogram: perintah tidak ditemukan
pamstereogram: príkaz nenájdený
pamstereogram: příkaz nenalezen
pamstereogram: команда не найдена
pamstereogram: командата не е открита
pamstereogram: 命令找不到
pamstereogram: コマンドが見つかりません