5 x 4017 Kaskade 40 LED

By doublestroke

A LED chaser over a square of 40 LEDs. 41 Would have been possible, i.e. if you plan a Circle instead of a Square. In this case connect another LED at Pin 8 of the last (upper left) 4017 and connect it's Pin 9 (instead of Pin 8) with the MR of the first 4017 (upper middle element).