Contents

class Integer
  def bell?
    in_sequence?(seq: :bell)
  end

  def bell
    n = self
    return 1 if zero?
    (0..(n-1)).map{|k| k.bell * (n-1).choose(k)}.reduce(:+)
  end

  memoize :bell
end

Version data entries

5 entries across 5 versions & 1 rubygems

Version	Path
numb-0.186.0	lib/numb/bell.rb
numb-0.185.0	lib/numb/bell.rb
numb-0.184.0	lib/numb/bell.rb
numb-0.181.0	lib/numb/bell.rb
numb-0.170.0	lib/numb/bell.rb