Fortran Permutations

program permutations
 
  implicit none
  integer ia
  integer, parameter :: value_min = 1
  integer, parameter :: value_max = 5
  integer, parameter :: position_min = value_min
  integer, parameter :: position_max = value_max
  integer, dimension (position_min : position_max) :: permutation
 
  call generate (position_min)
 
contains
 
  recursive subroutine generate (position)
 
    implicit none
    integer, intent (in) :: position
    integer :: value
 
    if (position > position_max) then
      ia=ia+1
      if(MOD(ia,2).ne.0) write (21, *) permutation
    if (permutation(1).eq.3.and.MOD(ia,2).ne.0) write(22,*) permutation
    else
      do value = value_min, value_max
        if (.not. any (permutation (: position - 1) == value)) then
          permutation (position) = value
          call generate (position + 1)
        end if
      end do
    end if
 
  end subroutine generate
 
end program permutations