Special-I - 421 - Frequency Divider

Difficulty: Kids
Author: Horst Ledpeddle

Special-I - 420 - Base 183

Difficulty: Kids
Author: Horst Ledpeddle

Special-I - 419 - Base 15 ''7B'' Diagonal

Difficulty: Kids
Author: Horst Ledpeddle

Special-I - 418 - Base 15 Type ''2A 3B''

Difficulty: Kids
Author: Horst Ledpeddle

Special-I - 417 - Base 15 Type ''7B''

Difficulty: Kids
Author: Horst Ledpeddle

Special-I - 416 - Base 7 Type ''3B''

Difficulty: Kids
Author: Horst Ledpeddle

Special-I - 415 - base 57 gray counter

Difficulty: Kids
Author: Alexis Monnerot