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

Terms

a(0) =197a(1) =424a(2) =828a(3) =1488a(4) =2519a(5) =4050a(6) =6252a(7) =9314a(8) =13479a(9) =19008a(10) =26224a(11) =35472a(12) =47169a(13) =61756a(14) =79754a(15) =101712a(16) =128267a(17) =160088a(18) =197940a(19) =242622a(20) =295041a(21) =356138a(22) =426970a(23) =508634a(24) =602351a(25) =709384a(26) =831128a(27) =969024a(28) =1124655a(29) =1299652