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A368860
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Number of beta-stable isotones of neutron number n.
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8
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1, 2, 1, 2, 2, 2, 2, 2, 2, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 0, 5, 0, 3, 1, 3, 1, 3, 1, 4, 1, 4, 1, 3, 1, 3, 0, 3, 1, 3, 0, 4, 1, 4, 1, 4, 0, 4, 1, 4, 1, 5, 1, 4, 1, 3, 2, 3, 1, 5, 1, 4, 0, 4, 1, 4, 1, 2, 1, 3, 1, 4, 0, 4, 1, 5, 1, 3, 1, 5, 1, 3, 1, 7, 1, 3, 2, 3, 1, 5, 0, 5
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OFFSET
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0,2
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COMMENTS
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A beta-stable nuclide is a nuclide whose beta decay (beta-minus and beta-plus decay) is energetically disallowed; that is to say, a nuclide that has lower energy than its isobars with one more or one less proton. Note that double beta decay is allowed. A nuclide whose beta decay is energetially allowed, even if not observed (in the case of 48Ca, 96Zr, 123Te, 148Gd, 180mTa, 222Rn and 247Cm), is not classified as being beta-stable.
We know 2 beta-stable isotopes with 160 neutrons (260Fm and 262No), but the unobserved nuclides 258Cf, 261No and 264Rf could be beta-stable as well.
Different from A318998: for N <= 126, 5He, 8Be, 146Sm, 150Gd, 154Dy, 210Po and 212Rn are beta-stable but not primordial. 40K, 48Ca, 50V, 96Zr, 113Cd, 115In, 123Te, 138La, 176Lu, 187Re and 180mTa are primordial but not beta-stable.
a(n) >= 2 for even 4 <= n <= 160, with a(n) = 2 for n = 4 (7Li and 8Be - the latter having an extremely short half-life), 6 (11B and 12C), 8 (15N and 16O), 66 (114Cd and 116Sn), 120 (198Pt and 200Hg) and 128 (212Po and 214Rn - both very unstable to alpha decay). a(82) = 7, and a(n) = 5 for n = 20, 50, 58, 74, 78, 88 and 90.
a(n) = 2 for odd n = 1 (2H and 3He), 3 (5He and 6Li - the former having an extremely short half-life), 5 (9Be and 10B), 7 (13C and 14N), 55 (97Mo and 99Ru) and 85 (145Nd and 147Sm). Page 12 of the Zagrebaev et al. link predicts that a(181) = 2 (corresponding to 293Cn and 295Fl).
Prediction of a(159)-a(187) from a Russian source: 1, 3, 1, 3, 1, 3, 1, 3, (0, 3 or 1, 2), 1, 4, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1, 3, 1.
Prediction of a(159)-a(209) from pages 14-15 of the Hiroyuki Koura link: 0, 5, 1, 3, 1, 4, 1, 4, 1, 4, 1, 3, 1, 5, 1, 4, 1, 5, 1, 4, 1, 5, 1, 4, 0, 6, 1, 4, 1, 3, 1, 4, 0, 4, 1, 4, 1, 3, 1, 5, 1, 3, 1, 4, 1, 3, 1, 4, 1, 2, 1.
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LINKS
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EXAMPLE
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a(56) = 3 because the beta-stable nuclides with 56 neutrons are 98Mo, 100Ru and 102Pd. Note that 96Zr is not beta-stable even if its beta decay has never been observed.
a(88) = 5 because the beta-stable nuclides with 88 neutrons are 148Nd, 150Sm, 151Eu, 152Gd and 154Dy, with the last one being not primordial.
a(126) = 4 because the beta-stable nuclides with 126 neutrons are 208Pb, 209Bi, 210Po and 212Rn, with the last two being not primordial.
a(158) = 4 because the beta-stable nuclides with 158 neutrons are 256Cf, 258Fm, 259Md and 260No.
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CROSSREFS
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KEYWORD
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nonn,fini,hard
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AUTHOR
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STATUS
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approved
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