Numbers k such that k^2 is a concatenation of two successive numbers.

Terms

a(0) =428a(1) =573a(2) =727a(3) =846a(4) =7810a(5) =36365a(6) =63636a(7) =326734a(8) =673267a(9) =4545454a(10) =5454547a(11) =47058823a(12) =52941178a(13) =331983807a(14) =332667334a(15) =384615386a(16) =422892898a(17) =475524477a(18) =524475524a(19) =577107103a(20) =615384615a(21) =667332667a(22) =668016194a(23) =719964246a(24) =758241758a(25) =804511280a(26) =810873337a(27) =857142859