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 A213374 #19 Sep 03 2012 07:13:27 %S A213374 2,6,8,14,16,20,28,32,38,40,50,58,64,76,80,82,90,100,114,118,124,126 %N A213374 Total number of states of the first n subshells of the nuclear shell model in which the subshells are ordered by energy level in increasing order. %C A213374 First differs from A212124 at a(14). For more information see A213372. %H A213374 MIT OpenCourseWare, <a href="http://www.flickr.com/photos/mitopencourseware/3772864128/in/set-72157621892931990">Energy Levels of Nucleons in a Smoothly-Varying Potential Well</a> %F A213374 a(n) = 2*A213373(n). %e A213374 Written as an irregular triangle in which row j is related to the j-th shell of nucleus. Note that row 4 has only one term. Triangle begins: %e A213374 2; %e A213374 6, 8; %e A213374 14, 16, 20; %e A213374 28; %e A213374 32, 38, 40, 50; %e A213374 58, 64, 76, 80, 82; %e A213374 90, 100, 114, 118, 124, 126; %e A213374 ... %e A213374 First seven terms of right border give the "magic numbers" A018226. %Y A213374 Partial sums of A213372. Other versions are A210984, A212014, A212124, A213364. %Y A213374 Cf. A018226, A213371, A213373. %K A213374 nonn,tabf,hard,more %O A213374 1,1 %A A213374 _Omar E. Pol_, Jul 16 2012