I'm curious about this as well. Hoping added interest will inspire a numbers guru. 
I'm sure someone more specific with the numbers will come along, but I'm pretty sure the chain is:
Blaze ---> Havoc Punch ---> Charged Brawl.
And you need about ~120% global recharge + Hasten to achieve that. Sorry if I'm inaccurate or totally wrong.
@Fail (Used to be @Tux) and @Tuxedo Infinitus Defiant/Freedom/Champion
Favourite Toons: Prosper [Ill/Rad] Controller :: Infinitus [Fire/Elec] Blaster :: Pocket Dynamo [Fire/Shield] Scr :: Fast [Cold/Sonic] Def ::
Inspire [Plant/Storm] Controller :: Quality - SS/Fire Brute :: Double Down [DP/Kin] Corr :: Pwnz [Fire/Cold] Corr :: Fail [Fire/Son] Corr
My search-fu, she is weak.
What's the top single-target DPS chain for a Fire/Elec Blaster and how much recharge do you need in each attack to make it happen?
And has someone written up a DPS comparison for Blaster sets?
Eva Destruction AR/Fire/Munitions Blaster
Darkfire Avenger DM/SD/Body Scrapper
Arc ID#161629 Freaks, Geeks, and Men in Black
Arc ID#431270 Until the End of the World