On: Collection Of Puzzles For Programmers

[vuknje]

Or in javascript..

  new Array(100).join(1).split(1)
    .map((function() { var i = 0; return function() {return ++i;}})())
    .filter(function(x) { return !(x % 15); })
    .reduce(function(x, a) { return a += x; }, 0);