Problem 15
(require 'calc-ext) (defvar calc-command-flags nil) (defun factorial (n) (let ((rst 1)) (while (math-lessp 0 n) (setq rst (math-mul rst n)) (setq n (math-sub n 1)) ) rst )) (let ((size (string-to-number (car argv)))) (princ (math-format-value (math-div (factorial (math-mul 2 size)) (math-pow (factorial size) 2)))) (princ "\n") )