Number of strictly increasing arrangements of 4 numbers in -(n+2)..(n+2) with sum zero.

Terms

a(0) =5a(1) =12a(2) =24a(3) =43a(4) =69a(5) =104a(6) =150a(7) =207a(8) =277a(9) =362a(10) =462a(11) =579a(12) =715a(13) =870a(14) =1046a(15) =1245a(16) =1467a(17) =1714a(18) =1988a(19) =2289a(20) =2619a(21) =2980a(22) =3372a(23) =3797a(24) =4257a(25) =4752a(26) =5284a(27) =5855a(28) =6465a(29) =7116