a(n) = A277713(n)/3.

Terms

a(0) =1a(1) =13a(2) =25a(3) =49a(4) =69a(5) =97a(6) =137a(7) =193a(8) =273a(9) =309a(10) =385a(11) =545a(12) =617a(13) =769a(14) =829a(15) =861a(16) =973a(17) =1089a(18) =1233a(19) =1301a(20) =1537a(21) =1657a(22) =1721a(23) =1945a(24) =2177a(25) =2465a(26) =2601a(27) =3073a(28) =3313a(29) =3441