A critical timing parameter from the datasheet is the (typically 60–120 ns at 10V). This delay defines how quickly the outputs change after a clock edge, limiting the maximum clock frequency to around 5–10 MHz depending on supply voltage.
The 4017 counter IC!
A 555 timer generates clock pulses, and each output lights an LED in sequence. The reset pin can be wired to any output to create shorter sequences (e.g., Q4 to reset for a 0–3 sequence). 4017 counter ic datasheet