a(n) = 2^n - 45 with n>5, a(5)=1.

Terms

a(0) =1a(1) =19a(2) =83a(3) =211a(4) =467a(5) =979a(6) =2003a(7) =4051a(8) =8147a(9) =16339a(10) =32723a(11) =65491a(12) =131027a(13) =262099a(14) =524243a(15) =1048531a(16) =2097107a(17) =4194259a(18) =8388563a(19) =16777171a(20) =33554387a(21) =67108819a(22) =134217683a(23) =268435411a(24) =536870867a(25) =1073741779a(26) =2147483603a(27) =4294967251