a(n) = (-1)^n * A000032(n) - 1.

Terms

a(0) =1a(1) =-2a(2) =2a(3) =-5a(4) =6a(5) =-12a(6) =17a(7) =-30a(8) =46a(9) =-77a(10) =122a(11) =-200a(12) =321a(13) =-522a(14) =842a(15) =-1365a(16) =2206a(17) =-3572a(18) =5777a(19) =-9350a(20) =15126a(21) =-24477a(22) =39602a(23) =-64080a(24) =103681a(25) =-167762a(26) =271442a(27) =-439205a(28) =710646a(29) =-1149852