Quarter-squares squared: A002620^2.

Terms

a(0) =0a(1) =0a(2) =1a(3) =4a(4) =16a(5) =36a(6) =81a(7) =144a(8) =256a(9) =400a(10) =625a(11) =900a(12) =1296a(13) =1764a(14) =2401a(15) =3136a(16) =4096a(17) =5184a(18) =6561a(19) =8100a(20) =10000a(21) =12100a(22) =14641a(23) =17424a(24) =20736a(25) =24336a(26) =28561a(27) =33124a(28) =38416a(29) =44100