censuslookup: 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/censuslookup - from package: regina-normal

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

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