100 LED chaser with multiple LEDs on at the same time
4017 output is 'one hot', and won't source much over 1mA, so you can't use that directly.

If you must employ a 4017, then the simplest way to get to a base-5 chase sequence is to use diode logic to connect the 10 outputs to the bases of 5 NPN driver transistors. So output Q0 connects by 2 diodes to TR0 and TR1 bases. Output Q1 connects by 2 diodes to TR1 and TR2 bases, etc etc. Total bill of materials 20 diodes, 5 current limiting resistors on the bases, and five transistors. If you use a driver array like ULN2803, then you don't even need the base current limiting resistors. That array goes up to 50v, so you can put LEDs in series to reduce the current requirement.

Finally, use an oscillator to drive the clock pin. A variable speed clock varies the speed of the chase.