a(n+2) = 2*a(n+1) + 2*a(n); a(0) = -1, a(1) = 1.

Terms

a(0) =-1a(1) =1a(2) =0a(3) =2a(4) =4a(5) =12a(6) =32a(7) =88a(8) =240a(9) =656a(10) =1792a(11) =4896a(12) =13376a(13) =36544a(14) =99840a(15) =272768a(16) =745216a(17) =2035968a(18) =5562368a(19) =15196672a(20) =41518080a(21) =113429504a(22) =309895168a(23) =846649344a(24) =2313089024a(25) =6319476736a(26) =17265131520a(27) =47169216512a(28) =128868696064a(29) =352075825152