a(n) = (A084218(n) - 1)/12.

Terms

a(0) =0a(1) =1a(2) =6a(3) =17a(4) =50a(5) =79a(6) =196a(7) =273a(8) =492a(9) =651a(10) =1210a(11) =1247a(12) =2366a(13) =2549a(14) =3656a(15) =4369a(16) =6936a(17) =6397a(18) =10830a(19) =10267a(20) =14314a(21) =15731a(22) =23276a(23) =19935a(24) =31300a(25) =30759a(26) =39858a(27) =40197a(28) =58870a(29) =47529