Warning: this is an htmlized version! The original is here, and the conversion rules are here.
```* (eepitch-lua51)
* (eepitch-kill)
* (eepitch-lua51)
Dn = {}
Dn[0] = {""}
Dn[1] = {"V"}

calcDn = function (n)
Dn[n] = {}
for _,s in ipairs(Dn[n-2]) do tinsert(Dn[n], "H"..s) end
for _,s in ipairs(Dn[n-1]) do tinsert(Dn[n], "V"..s) end
end
for i=2,12 do calcDn(i) end

PP(Dn[1])
PP(Dn[2])
PP(Dn[3])
PP(Dn[4])
PP(Dn[5])
PP(Dn[6])
PP(Dn[7])
PP(Dn[8])
PP(Dn[9])
PP(Dn[10])
PP(Dn[11])
PP(Dn[12])

-- replace = function (left, h, v, right

linha1 = function (s) return " "..string.gsub(s, "[HV]", {H="____", V="__"}):sub(2).." " end
linha2 = function (s) return "|"..string.gsub(s, "[HV]", {H="___|", V=" |"}) end
linha3 = function (s) return "|"..string.gsub(s, "[HV]", {H="___|", V="_|"}).."  "..s end
PD = function (domino) for _,f in ipairs{linha1, linha2, linha3} do print(f(domino)) end end
PD "HVVHH"
for _,d in ipairs(Dn[1]) do PD(d) end
for _,d in ipairs(Dn[2]) do PD(d) end
for _,d in ipairs(Dn[3]) do PD(d) end
for _,d in ipairs(Dn[4]) do PD(d) end
for _,d in ipairs(Dn[5]) do PD(d) end
for _,d in ipairs(Dn[6]) do PD(d) end

--
--                                                                            ___________
--                                                                           |___|___|___|
--                                                                           |___|___|___|  HHH
--                                                                            ___________
--                                                                           |___|___| | |
--                                                                           |___|___|_|_|  HHVV
--                                                                            ___________
--                                                                           |___| |___| |
--                                                                           |___|_|___|_|  HVHV
--                                                                            ___________
--                                                                           |___| | |___|
--                                                                           |___|_|_|___|  HVVH
--                                                                            ___________
--                                                                           |___| | | | |
--                                                                           |___|_|_|_|_|  HVVVV
--                                                       _________            ___________
--                                                      |___|___| |          | |___|___| |
--                                                      |___|___|_|  HHV     |_|___|___|_|  VHHV
--                                                       _________            ___________
--                                                      |___| |___|          | |___| |___|
--                                                      |___|_|___|  HVH     |_|___|_|___|  VHVH
--                                                       _________            ___________
--                                                      |___| | | |          | |___| | | |
--                                                      |___|_|_|_|  HVVV    |_|___|_|_|_|  VHVVV
--                                      _______          _________            ___________
--                                     |___|___|        | |___|___|          | | |___|___|
--                                     |___|___|  HH    |_|___|___|  VHH     |_|_|___|___|  VVHH
--                                      _______          _________            ___________
--                                     |___| | |        | |___| | |          | | |___| | |
--                                     |___|_|_|  HVV   |_|___|_|_|  VHVV    |_|_|___|_|_|  VVHVV
--                       _____          _______          _________            ___________
--                      |___| |        | |___| |        | | |___| |          | | | |___| |
--                      |___|_|  HV    |_|___|_|  VHV   |_|_|___|_|  VVHV    |_|_|_|___|_|  VVVHV
--           ___         _____          _______          _________            ___________
--          |___|       | |___|        | | |___|        | | | |___|          | | | | |___|
--          |___|  H    |_|___|  VH    |_|_|___|  VVH   |_|_|_|___|  VVVH    |_|_|_|_|___|  VVVVH
--  _        ___         _____          _______          _________            ___________
-- | |      | | |       | | | |        | | | | |        | | | | | |          | | | | | | |
-- |_|  V   |_|_|  VV   |_|_|_|  VVV   |_|_|_|_|  VVVV  |_|_|_|_|_|  VVVVV   |_|_|_|_|_|_|  VVVVVV
--

> for _,d in ipairs(Dn[6]) do PD(d) end

> ```