a(n) = 105 - 2^n.

Terms

a(0) =104a(1) =103a(2) =101a(3) =97a(4) =89a(5) =73a(6) =41a(7) =-23a(8) =-151a(9) =-407a(10) =-919a(11) =-1943a(12) =-3991a(13) =-8087a(14) =-16279a(15) =-32663a(16) =-65431a(17) =-130967a(18) =-262039a(19) =-524183a(20) =-1048471a(21) =-2097047a(22) =-4194199a(23) =-8388503a(24) =-16777111a(25) =-33554327a(26) =-67108759a(27) =-134217623a(28) =-268435351a(29) =-536870807