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Number of elements in the n-th period of the Janet periodic table of elements.
19

%I #18 Apr 10 2024 13:14:47

%S 2,2,8,8,18,18,32,32

%N Number of elements in the n-th period of the Janet periodic table of elements.

%C Essentially 2 followed by the first terms of A093907.

%C This puts Hydrogen and Helium in the first row, Lithium and Beryllium into the second, Boron to Magnesium into the third etc.

%H Mark R. Leach, <a href="https://www.meta-synthesis.com/webbook/35_pt/pt_database.php">The Internet Database of Periodic Tables</a>, Chemogenesis web book.

%H Albert Tarantola, <a href="https://web.archive.org/web/20230403214915/http://www.ipgp.fr/~tarantola/Files/Professional/Mendeleev/">PSE of Elements (Janet form)</a>.

%H Mark J. Winter, <a href="https://www.webelements.com/periodic_table_image_long.html">Image of the Janet long format (or 32-column) periodic table</a>, Web Elements Chemistry Nexus.

%t Flatten@ Table[2 (n #)^2 & /@ {-1, 1}, {n, 4}] (* _Michael De Vlieger_, Jul 22 2016 *)

%Y Cf. A093907, A137508, A138509, A137575.

%K nonn,less,fini,full

%O 1,1

%A _Paul Curtz_, Apr 26 2008

%E Edited by _R. J. Mathar_, Oct 02 2009