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A368860 Number of beta-stable isotones of neutron number n. 8
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 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
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.
LINKS
Hiroyuki Koura, Decay Modes and a limit of existence of nuclei, 4th International Conference on the Chemistry and Physics of the Transactinide Elements. (See here for an excerpted table.)
Valeriy Zagrebaev et al., Future of superheavy element research: Which nuclei could be synthesized within the next few years?, Journal of Physics: Conference Series, 420 (March 2013).
EXAMPLE
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.
CROSSREFS
Cf. A368859 (beta-stable isotopes), A367461 (isodiaphers), A318998.
Cf. A370457.
Sequence in context: A043533 A043558 A307359 * A297775 A043534 A043559
KEYWORD
nonn,fini,hard
AUTHOR
Jianing Song, Jan 08 2024
STATUS
approved

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Last modified May 23 14:50 EDT 2024. Contains 372763 sequences. (Running on oeis4.)