Data update

Task/Home-primes/Ruby/home-primes.rb

@@ -0,0 +1,18 @@
+require 'prime'
+
+def concat(n)
+  n.prime_division.map{|pr, exp| pr.to_s * exp }.join.to_i
+end
+
+def hp(n)
+  res = [n]
+  res << n = concat(n) until n.prime?
+  res
+end
+
+def hp_to_s(ar)
+  return "HP#{ar[0]}(1) = #{ar[0]}" if ar.size == 1
+  ar[0..-2].map.with_index(1){|n, i| "HP#{n}(#{(ar.size-i)}) = "}.join + ar.last.to_s
+end
+
+(2..20).each {|n| puts hp_to_s(hp(n)) }