Number of subsets of {1..n} with a subset summing to n.

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =10a(5) =23a(6) =47a(7) =102a(8) =207a(9) =440a(10) =890a(11) =1847a(12) =3730a(13) =7648a(14) =15400a(15) =31332a(16) =62922a(17) =127234a(18) =255374a(19) =514269a(20) =1030809a(21) =2071344a(22) =4148707a(23) =8321937a(24) =16660755a(25) =33384685a(26) =66812942a(27) =133789638a(28) =267685113a(29) =535784667