Just a note to mention that, besides the minor blues scale that @Luke mentions and that you @kjlarochelle show in your graphic, there is also the Major blues scale that is most commonly played (see the caveat at the end of this post) using the the following notes (for the C Major blues scale):
C D Eb E G A
or in general (using the numbers of the major scale tones):
I II bIII III V VI
This is just the C Major pentatonic with the bIII (= Eb) added. It is not easy to play the C Major blues scale on the C blues harp because of that bIII (Eb) which requires the advanced overblow technique on holes 1 and 4 (this is somewhat easier using a half-valved blues harp, where instead of the overblow on holes 1 and 4 you play a blow bend on holes 2 and 5, but it is still not so simple).
What is easier (if you have mastered the -3" and -3’) on the C harp is the G Major blues scale:
G A Bb B D E
played on the C harp as:
-2 -3" -3' -3 -4 +5
Unfortunately, the next octave’s Bb requires a hole 6 overblow … but up there you can just skip playing it and play the “plain” G Major pentatonic (at least when improvising) or buy a PowerBender harp in C where that Bb is now simply a draw 7 bend (-7’). 
As a final note: there is not just one minor blues scale, and not just one Major blues scale (at least in the world of music theory), but the ones given here by @Luke and myself are the most commonly used ones in the world of rock, blues and jazz.
Regards,
– Slim 