I built many such oscillators same way. But I used BC107 NPN, connected collector to the ground, emmiter to resistor/capacitornet. Base free. Add LED in series with such connected transistor, and you have LED blinker.

"Negative resistance"? Are you sure that's what you mean? Cuz it isn't.

Yes, it is... (negative differential resistance to be more precise)

https://en.wikipedia.org/wiki/Pearson%E2%80%93Anson_effect

https://en.wikipedia.org/wiki/Negative_resistance