p5.scm

(define sucesioncola
    (lambda (n)
        (letrec ([sc-do (lambda (a b c count)
                            (cond
                                ((= count 0) c)
                                (else
                                    (sc-do (+ a c) a b (- count 1)))))])
            (cond
                ((< n 3) n)
                (else (sc-do 2 1 0 n))))