Best NPK ratio

I'm grow outdoors and was wondering what the best NPK ratio would be for me.
Veg: either 20-20-20, 24-8-16, or 30-10-10
Also, would 15-30-15 be good for flowering.

Definitely need something like N heavy like 30-10-10 for veg.

I think flower is more 10-10-20.

Have a look at what the nute people do and that is your answer. Foxfarm Grow Big and Big Bloom - try and match those NPKs

For veg I usually go double on N than P, and K. So 10-5-5 20-10-10 that sort of thing. For flowering I go higher P than both N, and K. So your 15-30-15 would be good.

A lot of ppl forget about N when flowering, and the plant usually becomes N deficient. They still need a little N in early flowering, and even less when you really get buds kicking.