Right now, my absolute favorite is “cockpit” brown noise (the sound of muffled airline jet noise). For example, you could set this track to repeat endlessly: https://open.spotify.com/track/01Kk9an41cyVj7oIXd2Fsj?si=NnC...
For whatever reason, it gives me the feeling of “fast” (jet), important (I’m the pilot of this important thing?), and cozy (strapped in tight in the cockpit), and I never get the distracted (hmmm! What is this song?) feeling that I usually get from programming to music.
FYI: Difference between “white”, “pink”, & “brown” noise: https://www.soundofsleep.com/2017/07/18/white-pink-brown-noi...
White noise: equal energy per Hz (flat)
Pink noise: equal energy per octave (-3dB/octave)
Brown noise: spectrum of Brownian motion (-6dB/octave)
White and brown are easy to create mathematically.