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 A103205 #26 Sep 14 2019 14:54:31 %S A103205 0,1,2,3,4,5,6,7,8,19,10,11,12,13,14,15,16,17,18,29,20,21,22,23,24,25, %T A103205 26,27,28,39,30,31,32,33,34,35,36,37,38,49,40,41,42,43,44,45,46,47,48, %U A103205 59,50,51,52,53,54,55,56,57,58,69,60,61,62,63,64,65,66,67,68,79,70,71,72,73,74,75,76,77,78,89,80,81,82,83,84,85,86,87,88 %N A103205 Write numbers in decimal under each other, then read diagonals in upward direction. %C A103205 Decimal analog of A102370. %H A103205 Seiichi Manyama, <a href="/A103205/b103205.txt">Table of n, a(n) for n = 0..10000</a> %H A103205 David Applegate, Benoit Cloitre, Philippe Deléham and N. J. A. Sloane, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL8/Sloane/sloane300.html">Sloping binary numbers: a new sequence related to the binary numbers</a>, J. Integer Seq. 8 (2005), no. 3, Article 05.3.6, 15 pp. Preprint versions: [<a href="http://neilsloane.com/doc/slopey.pdf">pdf</a>, <a href="http://neilsloane.com/doc/slopey.ps">ps</a>]. %Y A103205 Cf. A102370 (base 2), A109681 (base 3), A325644 (base 4), A325645 (base 5), A325692 (base 6), A325693 (base 7), A325805 (base 8), A325829 (base 9), this sequence (base 10). %K A103205 nonn,easy,base %O A103205 0,3 %A A103205 _N. J. A. Sloane_, Mar 27 2005