Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.4.11)
// Compass (v1.0.3)
// ----

li{
  $follow: (
		1: 'tw',
		2: pin,
		3: in,
		4: gp,
		5: fb
	);
	content: #{map-get($follow, "1")};
@for $i from 1 through 5{
		&.#{map-get($follow, $i)}{
			background: url(img.png) no-repeat; 
			background-position: -170px - (( 13px + 32px )*$i) -150px;
		}
	} 
}

SassMeister-output.css

li.tw {
  background: url(img.png) no-repeat;
  background-position: -215px -150px;
}
li.pin {
  background: url(img.png) no-repeat;
  background-position: -260px -150px;
}
li.in {
  background: url(img.png) no-repeat;
  background-position: -305px -150px;
}
li.gp {
  background: url(img.png) no-repeat;
  background-position: -350px -150px;
}
li.fb {
  background: url(img.png) no-repeat;
  background-position: -395px -150px;
}