So I don't know why but I just wrote a minified credit card keygen in javascript by hand :P
for(;;){var L=0,Z="",Q=16;while(Z.length<Q)Z+=Math.floor(Math.random()*9.99);while(Q--){var T=parseInt(Z.charAt(Q-1),10)*2;if(T>8)T--;L+=T+parseInt(Z.charAt(Q--),10);}if(L%10===0&&L>0){Z=Z.substr(0,4)+"-"+Z.substr(4,4)+"-"+Z.substr(8,4)+"-"+Z.substr(12,4);console.log(Z);break;}}