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%I #31 Apr 15 2023 15:54:29
%S 1,1,1,1,0,1,1,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
%T 1,2,1,1,1,3,1,1,1,1,1,2,1,2,1,3,1,1,1,2,1,1,1,2,1,1,1,1,1,2,1,1,1,1,
%U 1,2,1,1,1,2,1,2,1,2,1,2,1,2,1,2,1,2,2
%N Number of stable nuclides with mass number n.
%C Radioactive nuclides with a half-life of 700 million years or greater (i.e., half-life longer than or equal to that of uranium-235) are included.
%C The last known term is a(294) = 0, although there is still an unconfirmed nuclide, oganesson-295.
%C Sum_{n=1..294} a(n) = 286, which is the number of known stable nuclides.
%C For n <= 209, a(n) = 0 only for n = 5, 8, while for n > 209, a(n) != 0 only for n = 232, 235 and 238 (thorium-232, uranium-235 and uranium-238).
%C The total number of stable nuclides with an even mass number is 176, while for odd mass number it's 110. Among all 176 even-mass-number stable nuclides, only 9 of them are with an odd number of protons and neutrons: hydrogen-2, lithium-6, boron-10, nitrogen-14, potassium-40, vanadium-50, lanthanum-138, lutetium-176 and tantalum-180.
%C There are 43 even numbers k such that a(k) = 1, 53 such that a(k) = 2 and 9 such that a(k) = 3. There are 100 odd numbers such that a(k) = 1 and only 5 such that a(k) = 2 (rubidium-87/strontium-87, cadmium-113/indium-113, indium-115/tin-115, antimony-123/tellerium-123, rhenium-187/osmium-187).
%H Jianing Song, <a href="/A318997/b318997.txt">Table of n, a(n) for n = 1..294</a>
%H Jianing Song, <a href="/A318997/a318997.txt">Stable nuclides with mass number n</a>
%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Table_of_nuclides_%28segmented,_narrow%29">Table of nuclides</a>.
%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Isobar_(nuclide)">Isobar</a>.
%e Stable nuclides with mass number n:
%e n = 36: sulfur-36, argon-36;
%e n = 40: argon-40, potassium-40, calcium-40;
%e n = 124: tin-124, tellurium-124, xenon-124.
%Y Cf. A179301 (proton number), A318998 (neutron number), A318999 (neutron excess).
%K nonn
%O 1,36
%A _Jianing Song_, Sep 07 2018
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