Number of nondecreasing integer sequences of length 6 with sum zero and sum of absolute values 2n.

Terms

a(0) =1a(1) =4a(2) =9a(3) =22a(4) =33a(5) =67a(6) =92a(7) =156a(8) =214a(9) =318a(10) =408a(11) =597a(12) =729a(13) =990a(14) =1221a(15) =1586a(16) =1885a(17) =2423a(18) =2820a(19) =3512a(20) =4090a(21) =4958a(22) =5674a(23) =6857a(24) =7729a(25) =9150a(26) =10335a(27) =12052a(28) =13441a(29) =15627