FUNCTION BESSK(N,X)
      IF (N.LT.2) PAUSE 'bad argument N in BESSK'
      TOX=2.0/X
      BKM=BESSK0(X)
      BK=BESSK1(X)
      DO 11 J=1,N-1
        BKP=BKM+J*TOX*BK
        BKM=BK
        BK=BKP
11    CONTINUE
      BESSK=BK
      RETURN
      END