Element, 10 bytes, crackedcracked
Output:
a(3) = 6561 a(4) = 4294967296 There's probably only a few ways to compute this sequence in Element. I found a 9-char solution, but I figured this 10-char solution is actually more difficult. The # are hidden characters.
#_####@^#` For convenience, here's the Try It Online and Esolang wiki pages.
The original was
2_3:~2@^^`