プロジェクト　オイラー117

FOR a=0 TO 50
FOR b=0 TO 50 STEP 2
FOR c=0 TO 50 STEP 3
FOR d=0 TO 50 STEP 4

        IF  a+b+c+d=50  THEN  LET s=s+fact(a+b/2+c/3+d/4)/(fact(a)*fact(b/2)*fact(c/3)*fact(d/4))
         
     NEXT D
  NEXT C

NEXT B
NEXT A
PRINT s
END