Number of subsets of {1..n} without a subset summing to n.

Terms

a(0) =0a(1) =1a(2) =2a(3) =3a(4) =6a(5) =9a(6) =17a(7) =26a(8) =49a(9) =72a(10) =134a(11) =201a(12) =366a(13) =544a(14) =984a(15) =1436a(16) =2614a(17) =3838a(18) =6770a(19) =10019a(20) =17767a(21) =25808a(22) =45597a(23) =66671a(24) =116461a(25) =169747a(26) =295922a(27) =428090a(28) =750343a(29) =1086245