Squares obtained as a concatenation of k and 10's complement of k.

Terms

a(0) =64a(1) =7921a(2) =9604a(3) =164836a(4) =351649a(5) =996004a(6) =19758025a(7) =20647936a(8) =29757025a(9) =30846916a(10) =97990201a(11) =99960004a(12) =1203187969a(13) =1975180249a(14) =3086469136a(15) =4265657344a(16) =8143618564a(17) =9999600004a(18) =115644884356a(19) =131504868496a(20) =132231867769a(21) =140039859961a(22) =173879826121a(23) =339900660100a(24) =391600608400