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 A212014 #23 Mar 14 2025 19:18:15 %S A212014 2,6,8,14,18,20,28,34,38,40,50,58,64,68,70,82,92,100,106,110,112,126, %T A212014 138,148,156,162,166,168,184,198,210,220,228,234,238,240,258,274,288, %U A212014 300,310,318,324,328,330,350,368,384,398,410,420,428,434,438,440,462,482,500,516,530,542,552,560,566,570,572 %N A212014 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. %D A212014 M. Goeppert Mayer, Nuclear configurations in the spin-orbit coupling model. I. Empirical evidence, Phys. Rev. 78: 16 (1950). II. Theoretical considerations, Phys. Rev. 78: 22 (1950). %H A212014 Paolo Xausa, <a href="/A212014/b212014.txt">Table of n, a(n) for n = 1..11325</a> (rows 1..150 of triangle, flattened). %F A212014 a(n) = 2*A212013(n). %e A212014 Example 1: written as a triangle in which row i is related to the (i-1)st level of nucleus. Triangle begins: %e A212014 2; %e A212014 6, 8; %e A212014 14, 18, 20; %e A212014 28, 34, 38, 40; %e A212014 50, 58, 64, 68, 70; %e A212014 82, 92, 100, 106, 110, 112; %e A212014 126, 138, 148, 156, 162, 166, 168; %e A212014 ... %e A212014 Column 1 gives positive terms of A033547. Right border gives positive terms of A007290. %e A212014 Example 2: written as an irregular triangle in which row j is related to the j-th shell of nucleus. In this case note that row 4 has only one term. Triangle begins: %e A212014 2; %e A212014 6, 8; %e A212014 14, 18, 20; %e A212014 28; %e A212014 34, 38, 40, 50; %e A212014 58, 64, 68, 70, 82; %e A212014 92, 100, 106, 110, 112, 126; %e A212014 138, 148, 156, 162, 166, 168, 184; %e A212014 ... %e A212014 First seven terms of right border give the "magic numbers" A018226. %t A212014 2*Accumulate[Flatten[Range[Range[15], 1, -1]]] (* _Paolo Xausa_, Mar 14 2025 *) %Y A212014 Partial sums of A212012. Other versions are A210984, A212124, A213364, A213374. %Y A212014 Cf. A004736, A007290, A033547, A018226, A212013. %K A212014 nonn,tabl,easy %O A212014 1,1 %A A212014 _Omar E. Pol_, Jul 15 2012