RosettaCodeData/Task/Bernoulli-numbers/PicoLisp/bernoulli-numbers.l
2023-07-01 13:44:08 -04:00

74 lines
1.8 KiB
Text

(load "@lib/frac.l")
(de fact (N)
(cache '(NIL) N
(if (=0 N) 1 (apply * (range 1 N))) ) )
(de binomial (N K)
(frac
(/
(fact N)
(* (fact (- N K)) (fact K)) )
1 ) )
(de A (N M)
(let Sum (0 . 1)
(for X M
(setq Sum
(f+
Sum
(f*
(binomial (+ N 3) (- N (* X 6)))
(berno (- N (* X 6)) ) ) ) ) )
Sum ) )
(de berno (N)
(cache '(NIL) N
(cond
((=0 N) (1 . 1))
((= 1 N) (-1 . 2))
((bit? 1 N) (0 . 1))
(T
(case (% N 6)
(0
(f/
(f-
(frac (+ N 3) 3)
(A N (/ N 6)) )
(binomial (+ N 3) N) ) )
(2
(f/
(f-
(frac (+ N 3) 3)
(A N (/ (- N 2) 6)) )
(binomial (+ N 3) N) ) )
(4
(f/
(f-
(f* (-1 . 1) (frac (+ N 3) 6))
(A N (/ (- N 4) 6)) )
(binomial (+ N 3) N) ) ) ) ) ) ) )
(de berno-brute (N)
(cache '(NIL) N
(let Sum (0 . 1)
(cond
((=0 N) (1 . 1))
((= 1 N) (-1 . 2))
((bit? 1 N) (0 . 1))
(T
(for (X 0 (> N X) (inc X))
(setq Sum
(f+
Sum
(f* (binomial (inc N) X) (berno-brute X)) ) ) )
(f/ (f* (-1 . 1) Sum) (binomial (inc N) N)) ) ) ) ) )
(for (N 0 (> 62 N) (inc N))
(if (or (= N 1) (not (bit? 1 N)))
(tab (2 4 -60) N " => " (sym (berno N))) ) )
(for (N 0 (> 400 N) (inc N))
(test (berno N) (berno-brute N)) )
(bye)