THE COEFFICIENTS OF RK4
            using the notation of Fehlberg, Bettis, Horn, et alia


  k	         a[k]

  0    0
  1    0.5
  2    0.5
  3    1


  k	         c[k]

  0    1/6
  1    1/3
  2    1/3
  3    1/6


 k     j	  ß[k,j] 

 1    0    0.5
 2    0    0
 2    1    0.5
 3    0    0
 3    1    0
 3    2    1