its called 50 and one :D
http://www.thegamehomepage.com/play/super-stacker-2/50-and-one/r550f55aq2Ur550f007a8Jt2b1H0J8o7Wt2b1H0J5H7Ct2b1H0J317gc1d1d554F82_c0p0p00Or1W1W001/
fyi on # 4 concatenate means to link together not to use math on or anythin... its carefully worded also placed... they use the word 'next' 6 therefor there are other #s after it... its called YAY! LOGiC after all