Numbers k such that k*(k+3) gives the concatenation of a number m with itself.

Terms

a(0) =8a(1) =98a(2) =767a(3) =858a(4) =910a(5) =998a(6) =3285a(7) =6713a(8) =9998a(9) =45452a(10) =54546a(11) =99998a(12) =990100a(13) =999998a(14) =8181819a(15) =9999998a(16) =70588233a(17) =99999998a(18) =343130554a(19) =362637363a(20) =363636361a(21) =420053631a(22) =421052632a(23) =497975709a(24) =502024289a(25) =578947366a(26) =579946367a(27) =636363637a(28) =637362635a(29) =656869444