.brick-list
  - 30.times do |i|
    .col
      %img{src: "http://hhhhold.com/jpeg/700?v=#{i}"}

@import "susy";
$grid: (1 2 5 5 2 1);
.col {
  &:nth-child(3n+1), &:nth-child(1) {
    @include span(2 at 1 of $grid);
  }
  &:nth-child(3n+2), &:nth-child(3) {
    @include span(2 at 3 of $grid);
  }
  &:nth-child(3n) {
    @include span(2 at 5 of $grid);
  }
  img {
    width: 100%;
  }
}