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 A158026 #4 Jun 09 2016 21:44:05 %S A158026 0,2,13,1597,1134903170,3416454622906707,10284720757613717413913, %T A158026 394810887814999156320699623170776339 %N A158026 Fibonacci numbers f such that all the digits needed to write the consecutive Fibonacci numbers from 0 to f fill exactly a square (no holes, no overlaps). %C A158026 The sides of the successive squares are given by A158027. Terms computed by Jean-Marc Falcoz. %H A158026 Eric Angelini, <a href="http://www.cetteadressecomportecinquantesignes.com/DigitSpiral.htm">Digit Spiral</a> %H A158026 E. Angelini, <a href="/A158022/a158022.pdf">Digit Spiral</a> [Cached copy, with permission] %e A158026 ...0...01...011...011235 %e A158026 .......12...235...813213 %e A158026 ............813...455891 %e A158026 ..................442333 %e A158026 ..................776109 %e A158026 ..................871597 %e A158026 The Fibonacci numbers fitting exactly in the SE corner of the above squares are 0, 2, 13, 1597. There are no 4x4 or 5x5 squares where this is possible. %K A158026 base,nonn %O A158026 1,2 %A A158026 _Eric Angelini_, Mar 11 2009