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A318997
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Number of stable nuclides with mass number n.
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3
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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, 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, 1, 2, 1, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 2
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OFFSET
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1,36
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COMMENTS
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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.
The last known term is a(294) = 0, although there is still an unconfirmed nuclide, oganesson-295.
Sum_{n=1..294} a(n) = 286, which is the number of known stable nuclides.
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).
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.
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).
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LINKS
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EXAMPLE
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Stable nuclides with mass number n:
n = 36: sulfur-36, argon-36;
n = 40: argon-40, potassium-40, calcium-40;
n = 124: tin-124, tellurium-124, xenon-124.
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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