The numbers in the hints of your levels: Special-I #249 (Trinary Counter I) and Special-I #250 (Trinary Counter II) need additional one, each.
At the end, the tank needs two moves (+ 2 turns), not one move (+ 1 turn).
#249:
After ODD number of moves, the tank is at M5 while the laser is still
traveling. The laser hits the block at M6. The block moves to M5 under
the tank. The tank needs two more moves to reach the flag. So: 3^23
+ 2 = 94,143,178,829.
#250:
Similar. Tank at M5. Laser from the left side hits Block at L5. Tank
on top, etc.
So: 29*(3^23) + 4*(3^2 + 3^4 + 3^6 + 3^7 + 3^9 + 3^11 +3^13 +
3^15 + 3^17 + 3^19 + 3^21) + 2 = 2,777,223,777,581. I was amazed
that you didn�t miss to include the 12 hits to the solid block at P6.
The counters are remarkable.
Regards,
Suyono H. Yaphar