puzzle - Formula to this pattern? $1$, $11$, $21$, $1211$, $111221

next 1221In the first row, there is one 1 (11). In the second, two 1s (21). In the third, there is one 2 then one 1 (1211). In the fourth, there is one 1 then one 2 then two 1s (111221). ItAngel number 1221 is a combination of the energies and vibrations of number 1 and number 2, with the number 2 appearing twice, amplifying its influence. Number 1 represents