Reflected tetranacci numbers A073817.

Terms

a(0) =4a(1) =-1a(2) =-1a(3) =-1a(4) =7a(5) =-6a(6) =-1a(7) =-1a(8) =15a(9) =-19a(10) =4a(11) =-1a(12) =31a(13) =-53a(14) =27a(15) =-6a(16) =63a(17) =-137a(18) =107a(19) =-39a(20) =132a(21) =-337a(22) =351a(23) =-185a(24) =303a(25) =-806a(26) =1039a(27) =-721a(28) =791a(29) =-1915