SassMeister-output.css

#mydiv {
  width: 2.12197;
}

.cols-1 {
  width: 1.12271em;
}

.cols-2 {
  width: 1.1896em;
}

.cols-3 {
  width: 1.26048em;
}

.cols-4 {
  width: 1.33558em;
}

.cols-5 {
  width: 1.41515em;
}

Understanding-sass-math-logic.scss

// ----
// Sass (v3.4.3)
// Compass (v1.0.1)
// ----

$notes:5;
//just cuz sass doesnt have enough math
@function expo($base,$exponent){
  $value:$base;
  @for $i from 1 through $exponent {
    $value:$value*$base;
  }
  @return $value;
}


//the function that can give me notes in HZ
@function octarray($n){
  $myarray:1;
  //that loop below
  
  @for $i from 1 through $n{
    $myarray:append($myarray,expo(105958,$i)/expo(100000,$i));
    //must use large number and deeevid because sass is stupid in maths and needs integers
  }
  $lastone: length($myarray);
  //variable that knows what n i stopped at, even though it could be equal to $n, should it? whatever this works
  @return nth($myarray,$lastone);
  //the last value in the array, because the function will be used this way gee
}


//this is not how it will actually work, but is an example
#mydiv{
  width:octarray(12);
}


//this is to make sure the loop itself gives me what i want
@for $i from 1 through $notes{
  .cols-#{$i}{
    width: 1* expo(105958,$i)/expo(100000,$i) +em;
  }
}

//fuck the police