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 A208090 #43 Feb 16 2025 08:33:16
%S A208090 110100100,10201,13330,400,324,202,244,271,100,121,144,169,172
%N A208090 100 written in base -n.
%H A208090 Phil Haacked, <a href="http://haacked.com/archive/2006/05/01/negativebasenumberingsystems.aspx">Negative Base Numering System</a>
%H A208090 Daniel Mondot, <a href="/A208090/a208090_2.txt">Bases to -101, including digits >9</a>
%H A208090 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Base.html">Base</a>
%t A208090 (* From MathWorld *) NegativeIntegerDigits[0, n_Integer?Negative] := {0}; NegativeIntegerDigits[i_, n_Integer?Negative] := Rest@Reverse@Mod[NestWhileList[(# - Mod[#, -n])/n &, i, # != 0 &], -n]; Table[FromDigits[NegativeIntegerDigits[100, -n]], {n, 2, 14}]
%Y A208090 Cf. A065004.
%K A208090 nonn,fini,full,less
%O A208090 2,1
%A A208090 _Radu Borza_, Mar 07 2012