%I #79 Mar 06 2022 09:04:46
%S 1,2,1,3,1,3,5,6,1,3,5,7,1,3,5,7,9,10,1,3,5,7,9,11,1,3,5,7,9,12,1,3,5,
%T 7,9,13,1,3,5,7,9,14,1,3,5,7,9,15,1,3,5,7,9,15,18,19,1,3,5,7,9,15,18,
%U 20,1,3,5,7,9,15,18,20,23,24,1,3,5,7,9,15,18,20,23,25
%N Irregular triangle read by rows in which row n lists the partial sums of shell numbers and respective number of electrons for all occupied shells of the n-th element of the periodic table of the elements.
%C The rows provide a way to distinguish the elements.
%C Electron Configurations for elements after Nobelium (atomic number 102), whose configuration of [RN] 5f14 7s2 comprises the last row of sequence, are at present unknown (see CRC Handbook in References).
%D Darleane C. Hoffman, Diana M. Lee, and Valeria Pershina, Transactinides and Future Elements, in Morss; Edelstein, Norman M.; Fuger, Jean (eds.). The Chemistry of Actinide and Transactinide Elements (3rd ed.). Dordrecht, The Netherlands (2006).
%D Catherine E. Housecroft and Alan G. Sharpe, Inorganic Chemistry (5th ed.). Pearson Education Limited. Harlow, England. (2018).
%D John R. Rumble (ed.), CRC Handbook of Chemistry and Physics, 100th edition. CRC Press. Boca Raton, Florida, 2019; Section 1, Electron Configuration and Ionization Energy of Neutral Atoms in the Ground State.
%H David Williams, <a href="/A335105/b335105.txt">Table of n, a(n) for n = 1..200, for rows 1-23 and part of 24</a>
%H Wikipedia, <a href="http://en.wikipedia.org/wiki/Electron_shell">Electron shell</a>
%e Lithium 1s2 2s1
%e 1+2+2+1
%e 1,3,5,6
%e Thus:
%e Hydrogen 1s1 1,2
%e Helium 1s2 1,3
%e Lithium 1s2 2s1 1,3,5,6
%e Beryllium 1s2 2s2 1,3,5,7
%e Boron 1s2 2s2 2p1 1,3,5,7,9,10
%Y Cf. A080915, A168208.
%K nonn,tabf,fini
%O 1,2
%A _David Williams_, May 23 2020