Number of subsets of {1..n} whose cardinality is equal to the average of the elements.

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =4a(5) =7a(6) =11a(7) =17a(8) =28a(9) =47a(10) =80a(11) =139a(12) =245a(13) =436a(14) =784a(15) =1419a(16) =2585a(17) =4738a(18) =8729a(19) =16154a(20) =30015a(21) =55966a(22) =104682a(23) =196378a(24) =369384a(25) =696494a(26) =1316252a(27) =2492683a(28) =4729673a(29) =8990374