|
if you look closely, you can see that the symbols change each time, and if you look carefully, you can see a diagonal row of symbols that are all the same,
consider these numbers 11, 13, and 15, you subtract the second digit in all of these numbers and you get 10, subtract another one and you get 9,
for 21, 25, 27, same thing, subtract the second digit and get 20, another two to get 18,
and the diagonal goes on and on 
|