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A368859 Number of beta-stable isotopes of the n-th element. 7
2, 3, 2, 2, 2, 2, 2, 3, 1, 3, 1, 3, 1, 3, 1, 4, 2, 3, 2, 5, 1, 5, 1, 4, 1, 4, 1, 5, 2, 5, 2, 5, 1, 6, 2, 6, 1, 4, 1, 4, 1, 7, 0, 7, 1, 6, 2, 7, 1, 10, 2, 7, 1, 9, 1, 7, 1, 4, 1, 7, 0, 8, 2, 8, 1, 8, 1, 6, 1, 7, 1, 6, 1, 5, 1, 7, 2, 6, 1, 7, 2, 4, 1, 6, 1, 6, 1, 7, 1, 7, 1, 7, 1, 6, 2, 5, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
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 7 beta-stable isotopes of californium (248-252, 254, 256) and fermium (252, 254, 256-260) respectively, but the unobserved nuclides 258Cf and 262Fm could be beta-stable as well.
Different from A179301: for Z <= 83, 5He, 8Be, 146Sm, 150Gd and 154Dy are beta-stable but not primordial. 40K, 48Ca, 50V, 96Zr, 113Cd, 115In, 123Te, 138La, 176Lu, 187Re and 180mTa are primordial but not beta-stable.
Page 12 of the Zagrebaev et al. link predicts that a(113) = 0.
Prediction of a(98)-a(118) from a Russian source: 7, 1, 7, 1, 7, 1, 7, (1, 6 or 2, 5), 1, 4, 1, 7, 1, 7, 1, 7, 1, 7, 1, 7.
Prediction of a(98)-a(125) from pages 14-15 of the Hiroyuki Koura link: 8, 1, 8, 2, 8, 1, 10, 1, 9, 1, 10, 1, 9, 1, 6, 2, 10, 1, 10, 2, 13, 1, 9, 1, 9, 1, 9, 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(2) = 3 because helium-3, -4 and -5 are beta-stable, even if helium-5 has an extremely short half-life.
a(4) = 2 because beryllium-8 and -9 are beta-stable, even if beryllium-8 has an extremely short half-life.
a(62) = 8 because the beta-stable isotopes of samarium are of mass numbers 144, 146-150, 152 and 154, with 146Sm being not primordial.
a(64) = 8 because the beta-stable isotopes of gadolinium are of mass numbers 150, 152, 154-158 and 160, with 150Gd being not primordial.
a(66) = 8 because the beta-stable isotopes of samarium are of mass numbers 154, 156, 158, 160-164, with 154Dy being not primordial.
a(84) = 6 because the beta-stable isotopes of polonium are of mass numbers 210-214 and 216.
CROSSREFS
Cf. A368860 (beta-stable isotones), A367461 (isodiaphers), A179301.
Cf. A368887.
Sequence in context: A297930 A031217 A064131 * A338238 A355077 A111497
KEYWORD
nonn,fini,hard
AUTHOR
Jianing Song, Jan 08 2024
STATUS
approved

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Last modified May 23 07:28 EDT 2024. Contains 372760 sequences. (Running on oeis4.)