Numbers of the form 2^i*3^j, i+j even.

Terms

a(0) =1a(1) =4a(2) =6a(3) =9a(4) =16a(5) =24a(6) =36a(7) =54a(8) =64a(9) =81a(10) =96a(11) =144a(12) =216a(13) =256a(14) =324a(15) =384a(16) =486a(17) =576a(18) =729a(19) =864a(20) =1024a(21) =1296a(22) =1536a(23) =1944a(24) =2304a(25) =2916a(26) =3456a(27) =4096a(28) =4374a(29) =5184