SEQUENCE GENERATOR (Behavioral) , To count the sequence 1,3,7,10,12,1,3,7,10. . . .

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_unsigned.ALL;
entity sg is
    Port ( clk,clr,pr : in  STD_LOGIC;
           q : inout  STD_LOGIC_VECTOR (3 downto 0));
end sg;
architecture Behavioral of sg is
begin
process(clk,clr,pr)
begin
if pr='0' then q<="1111";
elsif clr='0' then q<="0000";
elsif clk='0' and clk'event then
if q="0000" then q<="0001";
elsif q="1111" then q<="0001";
elsif q="0001" then q<="0011";
elsif q="0011" then q<="0111";
elsif q="0111" then q<="1010";
elsif q="1010" then q<="1100";
elsif q="1100" then q<="0001";
end if;
end if;
end process;
end Behavioral;