Flash a light in a specific pattern
The keyword from your text is "say". You apparently do not know exactly the pattern yet. 
This usually calls for an microcontroller. You can let your light flash with nearly any pattern using an microcontroller for less than 1 € or dollar. The best thing is: You can change your pattern without using a soldering iron. 

Of course there are possibilities with logic ICs too. Try to use a shift register like the sn54166. Preload the shift register with a dip switch. Give it a clock, e.g. from a NE555. Add another button to trigger the load input. 

The output will allow you to send a sequence with multiple durations of the clock cycle. If you need more elements to send, use a shift register with 16 bit. If you want to output the sequence continuously use a shift register with Input/Output and connect both the serial input and output.

As many here will simply say: "Go and buy a microcontroller" I'll give you some backup for trying it with logic circuitry.
So why should you do that? It seems you have little experience with logic circuitry otherwise you would not ask :). I consider a basic understanding of logic circuitry and the related nits and pieces as very valuable for fiddling with electronics in any way. And there is no better learning than by doing. 

The next thing is: Using a microcontroller may solve many problems with the very same platform or at least the same methodology, but it involves some rather difficult steps to get a grip on it. You need to get programming knowledge and you need do get knowledge about computing platforms in general to use it to your advantage.

If you want to learn more about logic circuitry go forward and try using them. If you just want to have a programmable flashlight and a programmable coffee machine and a programmable cat feeder and a programmable automatic TV station changer go and try an Arduino :)