3rd guess: another sequence! This one actually looks strangely close, but it's wrong at the high frequencies
6
運算式 7: StartAbsoluteValue, cos left parenthesis, "x" , right parenthesis plus cos left parenthesis, 2 "x" , right parenthesis plus cos left parenthesis, 4 "x" , right parenthesis plus cos left parenthesis, 8 "x" , right parenthesis , EndAbsoluteValuecosx+cos2x+cos4x+cos8x
7
4th guess: I think this one's the charm!
8
運算式 9: StartAbsoluteValue, cos left parenthesis, "x" , right parenthesis plus cos left parenthesis, 2 "x" , right parenthesis plus cos left parenthesis, 4 "x" , right parenthesis plus cos left parenthesis, 6 "x" , right parenthesis , EndAbsoluteValuecosx+cos2x+cos4x+cos6x
