screen_seq: command not found

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

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

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 Debian possible default full paths are:

/usr/lib/staden/bin/screen_seq - from package: staden

You may install the required package with command apt-get install {package}

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