dual-clock on 4017
Your question is a little confusing, Mozikluv. What are you trying to accomplish? Is the second 555 timer (B/mono) triggered off the first timer (A/astable), or does it have an independent trigger source?
The 4017 has two possible sources for an input clock, the Clock input and the Clock Enable input. Either one (or both) can be used as clock inputs, but they have opposite trigger polarities. A rising edge on the Clock input will increment the 4017 while the Clock Enable pin is held low, and a falling edge on the Clock Enable increments the counter while the Clock input is held high. One other difference between the two inputs, my datasheets show the Clock pin having a schmitt-trigger input, and the Clock Enable being a normal CMOS input (this may depend on the manufacturer). Hope this helps.