Sure, you can do this with CryptoCoinJS.

First download Node.js. Then do the following:

Make a new directory:

mkdir /tmp/myapp
cd /tmp/myapp

Initialize your app:

npm init

Then run:

npm install --save coinkey@1.1.0

Then run:

npm install --save coininfo@0.2.0

Create your js file:

touch app.js

Put the following:

var CoinKey = require('coinkey')
var ci = require('coininfo')

var amount = 10
//generate a bunch of Litecoin addresses
for (var i = 0; i < amount; ++i) {
  var ck = CoinKey.createRandom(ci('LTC').versions) //change LTC to BTC if you want Bitcoin
  console.log(ck.privateWif + ': ' + ck.publicAddress)
}

Run your script:

node app.js

Documentation for coinkey Documentation for coininfo.

Hope this helps. If something doesn't work, let me know.