Numbers of form 4 x^2 + 9 y^2.

Terms

a(0) =0a(1) =4a(2) =9a(3) =13a(4) =16a(5) =25a(6) =36a(7) =40a(8) =45a(9) =52a(10) =64a(11) =72a(12) =73a(13) =81a(14) =85a(15) =97a(16) =100a(17) =109a(18) =117a(19) =136a(20) =144a(21) =145a(22) =148a(23) =153a(24) =160a(25) =180a(26) =181a(27) =196a(28) =205a(29) =208