gistfile1.scm

(define pascal
  (lambda (x)
    (letrec ([last
               (lambda (x)
                 (if (null? (cdr x)) x (last (cdr x))))]
            [sum-two
              (lambda (x)
                (+ (car x) (cadr x)))]
            [sum-doubles
              (lambda (x)
                (cond ((null? (cdr x)) (last x))
                      (else (cons (sum-two x) (sum-doubles (cdr x))))))]
            [pascal-sub
              (lambda (x)
                (cons (car x) (sum-doubles x)))])
   (cond ((= x 1) (list 1))
       (else (pascal-sub (pascal (- x 1))))))))