seqsplit: 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/seqsplit - from package: biosquid

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

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