eulera Subroutine

public subroutine eulera(n, En)

Compute Euler number En

Arguments

Type IntentOptional Attributes Name
integer, intent(in) :: n

Serial number
real(kind=wp), intent(out) :: En(0:n)

En

Source Code

   subroutine eulera(n,En)

      integer,intent(in) :: n !! Serial number
      real(wp),intent(out) :: En(0:n)  !! `En`

      real(wp) :: r , s
      integer :: j , k , m

      En(0) = 1.0_wp
      do m = 1 , n/2
         s = 1.0_wp
         do k = 1 , m - 1
            r = 1.0_wp
            do j = 1 , 2*k
               r = r*(2.0_wp*m-2.0_wp*k+j)/j
            enddo
            s = s + r*En(2*k)
         enddo
         En(2*m) = -s
      enddo

   end subroutine eulera