// I was looking some fractal structures, with a friend who studies the maths, and we found a // simple algorithm. So i made some tweets with the formula. 

r{inf.do{|i|a=i.asInteger.rand2;if(a.even){a=a/2}{a=a*3+1};play{SinOsc.ar(a,0,0.1)!2*EnvGen.ar(Env.perc,1,1,0,1,2)};0.07.wait;}}.play
//
r{inf.do{|i|a=i.asInteger;if(a.even){a=a/2}{a=a*3+1};play{SinOsc.ar(a,0,0.1)!2*EnvGen.ar(Env.perc,1,1,0,1,2)};0.01.wait;}}.play
//
a=(-23);r{inf.do{a=a.asInteger;a.postln;if(a.even){a=a/2}{a=a*3+1};play{SinOsc.ar(a,0,0.1)!2*EnvGen.ar(Env.perc,1,1,0,1,2)};0.1.wait}}.play
//
a=(-917);r{inf.do{a=a.asInteger.postln;if(a.even){a=a/2}{a=a*3+1};play{SinOsc.ar(a,0,0.1)!2*EnvGen.ar(Env.perc,1,1,0,1,2)};0.1.wait}}.play

// the funny thing is that when you have a negative input this folds into a loop!

// the correct formula is this below
a=73;r=r{inf.do{a=a.asInteger;if(a==1){r.stop};if(a.even){a=a/2}{a=a*3+1};play{Blip.ar(a)!2*EnvGen.ar(Env.perc,1,1,0,1,2)};0.1.wait}}.play