repdigit

Noun

1. A number composed only of one or more occurrences of one specific digit and no other digit.
   • Repdigit Triangular Numbers [article title] - 1975, David W. Ballew, Ronald C. Weger, “Repdigit Triangular Numbers”, in Journal of Recreational Mathematics, volume 8, number 2, Farmingdale, N.Y.: Baywood Publishing Co.,...
   • Is there any system of notation in which there is a repdigit aa such that (aa)²#61;ccdd, with c#61;a-1 and d#61;c-1? - 1980 January, Murray S[eymour] Klamkin, quoting Charles W. Trigg, “The Olympiad Corner: 11”, in Crux...
   • Here is another palindromic magic square that has the added property of having main diagonals containing eight repeating "repdigits": 222, 333, 444, 555, 666, 777, 888, and 999. The magic sum is 2442. - 2002, Clifford...