1113213211...I think???
I had a similar logic game with alphabets in university.
1 (the first number)
- one 1 (which is if you write it 11)
11 (the second number)
- Two 1's (which if you write 21)
21 (the third)
- One 2, one 1 (when written 1211)
1211 (4th)
- one 1, one 2, two 1's (when written 111221)
1112211
- three 1, two 2, two 1 (when written 312211
312211
- one 3, one 1, two 2, two 1 (when written 13112221)
13112221
- one 1, one 3, two 1, three 2 one 1 (when written 1113213211)
By the way, it describes the one before
In university we are trained to see these things, be it right or wrong, in programming class we are put through death with these lol.