Numbers whose square is the concatenation of two numbers k and k+4.

Terms

a(0) =2a(1) =310a(2) =453a(3) =548a(4) =691a(5) =856a(6) =4382a(7) =5619a(8) =72730a(9) =346533a(10) =653468a(11) =9090908a(12) =94117646a(13) =334665333a(14) =336032387a(15) =378253328a(16) =390977442a(17) =439928491a(18) =483516486a(19) =516483515a(20) =560071510a(21) =609022559a(22) =621746673a(23) =663967614a(24) =665334668