Numbers k such that the concatenation of k with k+9 gives a square.

Terms

a(0) =216a(1) =287a(2) =515a(3) =675a(4) =1175a(5) =4320a(6) =82640a(7) =960795a(8) =1322312a(9) =4049591a(10) =16955015a(11) =34602080a(12) =171010235a(13) =181964891a(14) =183673467a(15) =187160072a(16) =321920055a(17) =326530616a(18) =328818032a(19) =343942560a(20) =470954312a(21) =526023432a(22) =528925616a(23) =534830855