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 A044880 #6 Nov 26 2024 13:53:04
%S A044880 730,731,732,733,734,735,736,737,739,749,759,769,779,789,799,809,811,
%T A044880 812,813,814,815,816,817,818,828,829,831,832,833,834,835,836,837,838,
%U A044880 839,841,842,843,844,845,846,847,848,849,851
%N A044880 In base 9, (sum of even run lengths)=(sum of odd run lengths).
%t A044880 Select[Range[1000],With[{lens=Length/@Split[IntegerDigits[#,9]]},Total[Select[lens,OddQ]]==Total[Select[lens,EvenQ]]]&] (* _Harvey P. Dale_, Nov 26 2024 *)
%K A044880 nonn,base
%O A044880 1,1
%A A044880 _Clark Kimberling_