Column k=2 sequence of array A103728.

Terms

a(0) =1a(1) =5a(2) =13a(3) =41a(4) =61a(5) =113a(6) =145a(7) =221a(8) =365a(9) =421a(10) =613a(11) =761a(12) =841a(13) =1013a(14) =1301a(15) =1625a(16) =1741a(17) =2113a(18) =2381a(19) =2521a(20) =2965a(21) =3281a(22) =3785a(23) =4513a(24) =4901a(25) =5101a(26) =5513a(27) =5725a(28) =6161a(29) =7813