35506

Choose a small random number (e.g. 1) if a light lights up pick another number of the same quality (e.g. 3 both odd).If the same light lights up then try another odd number (e.g. 5). If the same light lights up on all three of them you have one of the lights (odd numbers). If this does not work go through the sequence again with different numbers, repeat until all the lights are found.