CLS
R = 12 : C = 40
FOR L = 1 TO 20
  FOR i = 1 TO L
    SELECT CASE L - (L \ 4) * 4
    CASE 0
      C = C + 2
    CASE 1
      R = R + 1
    CASE 2
      C = C - 2
    CASE 3
      R = R - 1
    END SELECT
    LOCATE R, C : PRINT "#";
  NEXT
NEXT