June 2018 Update

Task/Left-factorials/Ruby/left-factorials-1.rb

@@ -1,8 +1,7 @@
 left_fact = Enumerator.new do |y|
-  n, f, lf = 0, 1, 0
-  loop do
+  f, lf = 1, 0
+  1.step do |n|
     y  << lf #yield left_factorial
-    n  += 1
     lf += f
     f  *= n
   end

Task/Left-factorials/Ruby/left-factorials-2.rb

@@ -1,8 +1,12 @@
-left_fact = Enumerator.new do |y|
-  f, lf = 1, 0
-  1.step do |n|
-    y  << lf #yield left_factorial
-    lf += f
-    f  *= n
+tens = 20.step(110, 10)
+thousands = 1000.step(10_000, 1000)
+
+10001.times do |n|
+  lf = left_fact.next
+  case n
+  when 0..10, *tens
+    puts "!#{n} = #{lf}"
+  when *thousands
+    puts "!#{n} has #{lf.to_s.size} digits"
   end
 end