You could also use a binary count of 0, 1, 3, 7 then repeat. this gives:
000
001
011
111
restart
Use the outputs of the counter to drive FET's and you are all set. Get the clock frequency right and the sequence will happen at the right speed. Gate the outputs so they blank after reaching 7, but keep counting to 15 then reset. Since the clock rate is fixed, getting to 15 will take twice the time as 7, so half the time the outputs will be off, giving the full off time between cycles.
You could do this with a 4029 counter, a 555 for clock ( or an inverter 40106 ) and maybe a 4070 xor to gate the outputs when counting from 8-15.