パスカルの三角形をRubyで実装してみました。PascalsTriangle.new.run(10)で数字を出力、PascalsTriangle.new.run(40, 'fractal')でフラクタル図形を描画します。（fractalの場合はCOUNTを40くらいにするとよいです）

pascals_traiangle.rb

# encoding: utf-8

class PascalsTriangle
  @@count= 10
  @@list = []

  def create(list)
    sum = []
    i = 1
    while i < list.size
      sum.push(list[i - 1] + list[i])
      i+=1
    end
    return [1] + sum + [1]
  end

  def show(list, mode='normal')
    i = 0
    list.each do |x|
      space = ((@@count - i) / 2) * 2
      space-=1  if i % 2 == 0
      space.times {print " "}

      case mode
      when 'fractal'
        self.show_fractal(x)
      else
        self.show_normal(x)
      end

      i+=1
    end
  end

  def show_normal(list)
    print list * " "
    print "\n\n"
  end

  def show_fractal(list)
    list.each_index do |i|
      if list[i] % 2 == 0 then
        list[i] = "●"
      else
        list[i] = "○"
      end
    end

    print list * " "
    print "\n"
  end

  def run(count=10, mode='normal')
    @@count = count
    @@count.times do |x|
      @@list[x] = [1] if x == 0
      @@list[x] = [1, 1] if x == 1
      next if x <= 1
      @@list[x] = self.create(@@list[x - 1])
    end
    self.show(@@list, mode)
  end
end

PascalsTriangle.new.run(10)