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 A199934 #19 Jun 16 2022 03:21:52 %S A199934 21,22,23,24,25,26,27,28,29,30,39,40,41,42,43,44,45,46,47,48,71,72,73, %T A199934 74,75,76,77,78,79,80,103,104,105,106,107,108,109,110,111,112,153,154, %U A199934 155,156,157,158,159,160,161,162,203,204,205,206,207,208,209,210,211,212,275,276,277,278,279,280,281,282,283,284,347 %N A199934 Extended d-block elements for Janet table. %C A199934 After the s-block (A160914) and the p-block (A138469), we present the d-block (4*10) elements for the Janet table, in A167268. Janet published his table in a 1928 book (see below), 24 of planche 7, in which he also introduced the s, p, d, f blocks (called nappes 1, 2, 3, 4). %C A199934 a(n) also comes from one of the two classical Mendeleyev-Moseley-Seaborg periodic table(s) i.e. (see A138096): %C A199934 1 2 %C A199934 3 4 5 to 10 %C A199934 11 12 13 to 18 %C A199934 19 20 21 to 30 31 to 36 %C A199934 37 38 39 to 48 49 to 54 %C A199934 55 56 57 to 70 71 to 80 81 to 86 %C A199934 87 88 89 to 102 103 to 112 113 to 118. %C A199934 (The second is in A134982). %D A199934 Charles Janet, Essais de classification hélicoidale des éléments chimiques, April 1928, N3, Beauvais, 2 + 104 pages, 4 leaflets (4 to 7). %H A199934 Wikipedia, <a href="http://en.wikipedia.org/wiki/Charles_Janet">The Janet periodic table</a> %K A199934 nonn,tabf %O A199934 1,1 %A A199934 _Paul Curtz_, Nov 12 2011