a(n) = number of ways the set {1,2,...,n} can be split into proper subsets with equal sums.

Terms

a(0) =0a(1) =0a(2) =1a(3) =1a(4) =1a(5) =1a(6) =5a(7) =11a(8) =10a(9) =1a(10) =79a(11) =165a(12) =1a(13) =664a(14) =2917a(15) =3308a(16) =9295a(17) =23729a(18) =31874a(19) =301029a(20) =422896a(21) =1a(22) =13716866a(23) =71504979a(24) =100664384a(25) =54148590a(26) =880696661a(27) =498017758a(28) =27450476786a(29) =111911522818