A058318 - OEIS

%I #47 Apr 25 2024 11:35:49

%S 1,1,2,2,2,2,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,

%T 4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,6,6,6,6,

%U 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7

%N Number of energy levels in atoms of the n-th element of the periodic table.

%C Run lengths, i.e., how many elements have 1,2,3,4,5,6,7 energy levels, are 2,8,8,18,18,32,26 (see A137583).

%H Y. Bentor, <a href="http://www.chemicalelements.com/">Chemical Elements.Com</a>

%H M. Winter, <a href="http://www.webelements.com/webelements/scholar/index.html">WebElements Periodic Table</a>.

%F a(n) = m for s(m-1) < n <= s(m) for m=1..7, where s(m) = A173592(m) and s(0) = 0. - _Michel Lagneau_, Apr 03 2024

%e For n=79, element 79 (Gold) has a(79)=6 energy levels (which may have 2,8,18,32,18,1 electrons).

%p seq(i$[2, 8, 8, 18, 18, 32, 32][i], i=1..7); # _Michel Lagneau_, Apr 03 2024

%Y Cf. A007656, A018227, A058317, A137583, A173592.

%K nonn,fini,full

%O 1,3

%A _Labos Elemer_, Dec 12 2000

%E a(106)-a(118) from _Michel Lagneau_, Apr 03 2024