a(n) = a(n-1) + a(n-2) + (-1)^n, with a(0)=0 and a(1)=1.

Terms

a(0) =0a(1) =1a(2) =2a(3) =2a(4) =5a(5) =6a(6) =12a(7) =17a(8) =30a(9) =46a(10) =77a(11) =122a(12) =200a(13) =321a(14) =522a(15) =842a(16) =1365a(17) =2206a(18) =3572a(19) =5777a(20) =9350a(21) =15126a(22) =24477a(23) =39602a(24) =64080a(25) =103681a(26) =167762a(27) =271442a(28) =439205a(29) =710646