Can someone explain to me how to output the sequence "100, 81, 64, 49, 36, 25, 16, 9, 4, 1" in C++?

I am only able to use 1 variable and cannot use multiplication(*) or addition(+).

I understand that it is subtracting by 19,17,15,13,etc... but i cannot figure out how to acquire that sequence with just one variable, when that variable would likely be assigned to 100.