Number of nondecreasing arrangements of 6 numbers in -(n+4)..(n+4) with sum zero.

Terms

a(0) =338a(1) =676a(2) =1242a(3) =2137a(4) =3486a(5) =5444a(6) =8196a(7) =11963a(8) =17002a(9) =23612a(10) =32134a(11) =42955a(12) =56512a(13) =73294a(14) =93844a(15) =118765a(16) =148718a(17) =184430a(18) =226694a(19) =276373a(20) =334402a(21) =401792a(22) =479632a(23) =569093a(24) =671430a(25) =787986a(26) =920192a(27) =1069575a(28) =1237756a(29) =1426456