18k^2-12k-7 interleaved with 18k^2+6k+5 for k>=0.

Terms

a(0) =-7a(1) =5a(2) =-1a(3) =29a(4) =41a(5) =89a(6) =119a(7) =185a(8) =233a(9) =317a(10) =383a(11) =485a(12) =569a(13) =689a(14) =791a(15) =929a(16) =1049a(17) =1205a(18) =1343a(19) =1517a(20) =1673a(21) =1865a(22) =2039a(23) =2249a(24) =2441a(25) =2669a(26) =2879a(27) =3125a(28) =3353a(29) =3617