As a command
$ fibs 10 1 1 2 3 5 8 13 21 34 55
As a library
require 'fibs' p Fibs.(10) #=> [1, 1, 2, ..., 55]
Or
require 'fibs' p Fibs.new(1, 1).take(10) #=> [1, 1, 2, ..., 55]
require 'fibs' Fibs.new(1, 1).each do |x| ... end