a(n)=T(n,n+2), array T as in A048149.

Terms

a(0) =6a(1) =13a(2) =22a(3) =33a(4) =50a(5) =69a(6) =90a(7) =117a(8) =142a(9) =175a(10) =208a(11) =247a(12) =290a(13) =329a(14) =380a(15) =427a(16) =482a(17) =539a(18) =592a(19) =663a(20) =726a(21) =797a(22) =866a(23) =937a(24) =1022a(25) =1101a(26) =1188a(27) =1275a(28) =1362a(29) =1461