Fortran code to calculate series.

series.f95

!****************************************************
! 級数計算
! : SUM((1/i) * (2/(i+1)) * (3/(i+2))) を計算する
!
! date          name            version
! 2017.04.10    mk-mode.com     1.00 新規作成
!
! Copyright(C) 2017 mk-mode.com All Rights Reserved.
!****************************************************
!

program series
  implicit none
  integer, parameter :: terms = 1000
  real, dimension(terms) :: x, y, z
  integer :: i

  do i = 1 , terms
     x(i) = 1.0 /  i
     y(i) = 2.0 / (i + 1)
     z(i) = 3.0 / (i + 2)
  end do

  print *, 'ANSWER = ', sum(x * y * z)

end program series