Numbers k such that k * (k+9) is the concatenation of a number m with itself.

Terms

a(0) =2a(1) =92a(2) =420a(3) =572a(4) =693a(5) =728a(6) =992a(7) =9855a(8) =9992a(9) =36355a(10) =63637a(11) =99992a(12) =970298a(13) =999992a(14) =4545455a(15) =5454537a(16) =9999992a(17) =88235295a(18) =99999992a(19) =351069983a(20) =403018035a(21) =493927126a(22) =506072866a(23) =596981957a(24) =648930009a(25) =736842097a(26) =739839100a(27) =766233767a(28) =769230761a(29) =827751188