seqxref: 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/bin/seqxref - from package: emboss

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

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