With a 555 + 4017, how do I light 7 LEDs, then 6, then 5... then 1 then 0?
There are many ways to do this, some include a bag of diodes.. or a micro, which would be overkill in my opinion.

The simplest is just to cascade some OR gates.







simulate this circuit &ndash; Schematic created using CircuitLab

However : If that is all these outputs are being used for, you are using the wrong part here. You should consider using a shift register instead. Perhaps a CD4015.







simulate this circuit

NOTE: Resistors shown are for 5V Vdd.