Cannot install NodeJs: /usr/bin/env: node: No such file or directory

I'm trying to install nodeJs into my Ubuntu 14.04 in order to use GruntJs.

I've read about Ubuntu different way of doing it (issues?), so this is what I've done in order to install it:

sudo apt-get install npmsudo npm install -g grunt-cli

Typing grunt after that I've got the error:

/usr/bin/env: node: No such file or directory

So, I've tried:

curl -sL https://deb.nodesource.com/setup | sudo bash -sudo apt-get install -y nodejssudo apt-get update

And trying again, and still getting the error, I've tried:

sudo add-apt-repository https://launchpad.net/~chris-lea/+archive/node.js/sudo apt-get install -y nodejs

I've got this message:

nodejs is already the newest version.0 to upgrade, 0 to newly install, 0 to remove and 3 not to upgrade.

I did try a cleanup just in case:

sudo apt-get autoremove

But nope, the error is still there: when I type grunt I still get /usr/bin/env: node: No such file or directory

What should I do?