program test
      implicit none
c
      integer, parameter :: ntable = 1000
      integer n
      double precision, dimension(ntable) :: result
      double precision, external :: lfak
c
      do n=1,ntable
       result(n) = lfak(n)
      enddo
c
      write(*,'(1x,3a15)') 'n','log10(n!)','n!'
      do n=1,ntable,5
       write(*,'(1x,i15,1p,2d15.5)') n,result(n),10.d0**result(n)
      enddo
c
      stop 
      end
c
c
c
      double precision function lfak(n)
      implicit none
      integer, intent(in) :: n
c
      integer i
c
      if(n .le. 1) then
       lfak = 0.d0
       return
      else
       lfak = 0.d0
       do i=2,n
        lfak = lfak + log10(dble(i))
       enddo
      endif
      return
      end