Number of n element multisets of length 4 vectors over GF(2) that sum to zero.

Terms

a(0) =1a(1) =1a(2) =16a(3) =51a(4) =276a(5) =969a(6) =3504a(7) =10659a(8) =30954a(9) =81719a(10) =205040a(11) =482885a(12) =1088100a(13) =2340135a(14) =4850640a(15) =9694845a(16) =18789795a(17) =35357670a(18) =64833120a(19) =115997970a(20) =203014680a(21) =347993910a(22) =585292320a(23) =966955410a(24) =1571349780a(25) =2514084066a(26) =3964589856a(27) =6167026726a(28) =9470900056a(29) =14369476066