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 A034991 #10 Oct 09 2019 03:04:38 %S A034991 729,7744,777924,77774761,77777400996,777777594889,77777777127241, %T A034991 77777777127241,7777777771566496516,7777777777144230025, %U A034991 777777777770200337601,777777777777430543201344,77777777777778331004281924,77777777777777489970787004164,7777777777777771308012741325056,777777777777777744351960257494201,7777777777777777716034080781138596 %N A034991 Smallest square starting with a string of n 7's. %D A034991 David Wells, 'Curious and Interesting Numbers', Penguin Books 1988, p. 184. %Y A034991 Cf. A034990. %K A034991 nonn,base %O A034991 1,1 %A A034991 _Patrick De Geest_, Nov 15 1998 %E A034991 More terms from Francisco Salinas (franciscodesalinas(AT)hotmail.com), Dec 23 2001