This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A137434 #12 Jan 14 2023 08:44:00 %S A137434 1,121,1444,44944,6441444,47444544,4434494464,44424414441, %T A137434 1113111511681,22222220262025,444431244445444,22292262226224225, %U A137434 441544444344443449,1113101111111117041,2222222222222640225,11111119101145491111121 %N A137434 a(n) = smallest square containing n copies of the same nonzero digit. %e A137434 a(9) = 1113111511681 because there is no smaller square number with 9 copies of the same nonzero digit. a(9) has 9 1's. %Y A137434 Cf. A036508, A036509, A036510, A036511, A036512, A036513, A036514, A036515, A036516. - _Jon E. Schoenfield_, Jan 14 2009 %K A137434 nonn,base,more %O A137434 1,2 %A A137434 _Randy L. Ekl_, Apr 17 2008 %E A137434 Edited by _N. J. A. Sloane_ at the suggestion of _Jon E. Schoenfield_, Jan 11 2009 %E A137434 a(12)-a(15) from _Jon E. Schoenfield_, Jan 14 2009 %E A137434 a(16) from _Jon E. Schoenfield_, Jan 17 2009