Number of different ways to select 3 disjoint subsets from {1..n} with equal element sum.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =3a(6) =8a(7) =22a(8) =63a(9) =157a(10) =502a(11) =1562a(12) =4688a(13) =15533a(14) =50953a(15) =165054a(16) =562376a(17) =1911007a(18) =6467143a(19) =22447463a(20) =78021923a(21) =271410289a(22) =957082911a(23) =3384587525a(24) =11998851674a(25) =42876440587a(26) =153684701645a(27) =552421854011