nOrder=4
dim xy$(40)
for i = 1 to 40
    xy$(i) = "                               "
next i
call triangle 1, 1, nOrder
for i = 1 to 36
    print xy$(i)
next i
end

SUB triangle x, y, n
    IF n = 0 THEN
        xy$(y) = left$(xy$(y),x-1) + "*" + mid$(xy$(y),x+1)
    ELSE
        n=n-1
        length=2^n
        call triangle x, y+length, n
        call triangle x+length, y, n
        call triangle x+length*2, y+length, n
    END IF
END SUB