If you love solving problems related to progressions and series, then "SICK-QUENCES" is just the best thing for you. It covers many of the comprehensive problems, through which you can hone your skills!
These SICK-seQUENCES are purely for those want to develop their skills in these type of problems and these sequences may be sick, but they can help you get well-sequenced!!
Even if you don't know how to proceed then don't worry, solutions are also posted with the problem itself. So learn from one and execute it in other problems!