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A335105 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. 0
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, 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, 20, 1, 3, 5, 7, 9, 15, 18, 20, 23, 24, 1, 3, 5, 7, 9, 15, 18, 20, 23, 25 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The rows provide a way to distinguish the elements.

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).

REFERENCES

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).

Catherine E. Housecroft and Alan G. Sharpe, Inorganic Chemistry (5th ed.). Pearson Education Limited. Harlow, England. (2018).

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.

LINKS

Table of n, a(n) for n=1..84.

Wikipedia, Electron shell

EXAMPLE

Lithium 1s2 2s1

        1+2+2+1

        1,3,5,6

Thus:

Hydrogen  1s1           1,2

Helium    1s2           1,3

Lithium   1s2 2s1       1,3,5,6

Beryllium 1s2 2s2       1,3,5,7

Boron     1s2 2s2 2p1   1,3,5,7,9,10

CROSSREFS

Cf. A080915, A168208.

Sequence in context: A308673 A324287 A213594 * A325252 A243334 A234809

Adjacent sequences:  A335102 A335103 A335104 * A335106 A335107 A335108

KEYWORD

nonn,tabf,fini,more

AUTHOR

David Williams, May 23 2020

STATUS

approved

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Last modified July 31 04:58 EDT 2021. Contains 346367 sequences. (Running on oeis4.)