A367461 - OEIS

%I #22 Feb 22 2024 20:09:32

%S 0,0,0,0,0,0,0,2,14,17,11,5,8,8,9,3,8,5,10,9,10,5,8,4,7,1,6,2,7,4,9,6,

%T 9,5,9,2,7,3,7,5,7,3,6,5,6,2,4,4,5,2,6,4,6,5,5,3,6,3,5,4,6,4,6,3

%N Number of beta-stable nuclides with neutron excess n, i.e., (neutron number) - (proton number) = n.

%C n = -8 represents the most proton-rich nuclide known (nickel-48). 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.

%C We know of 5 beta-stable nuclides with neutron excess 56 (244Pu, 248Cm, 252Cf, 256Fm, 260No), and it is almost sure that a(56) = 6 with the sixth beta-stable nuclide being the unobserved 264Rf.

%C Different from A318999: 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.

%C Prediction of a(56)-a(65) from a Russian source: 6, 3, 5, 3, 6, (2, 6, 6 or 3, 6, 5), 6, 3.

%C Prediction of a(56)-a(85) from pages 14-15 of the Hiroyuki Koura link: 6, 2, 6, 2, 6, 3, 7, 3, 7, 3, 7, 3, 8, 4, 8, 4, 6, 2, 5, 2, 5, 1, 5, 3, 6, 3, 6, 3, 7, 3.

%H Hiroyuki Koura, <a href="http://tan11.jinr.ru/pdf/10_Sep/S_2/05_Koura.pdf">Decay Modes and a limit of existence of nuclei</a>, 4th International Conference on the Chemistry and Physics of the Transactinide Elements. (See <a href="https://en.wikipedia.org/wiki/User:ComplexRational/Isotopes#Beta-stable_isotopes_of_superheavy_elements">here</a> for an excerpted table.)

%H Web Archive, <a href="https://web.archive.org/web/20131217155419/http://wsyachina.narod.ru/physics/all_matter/sist-1a.jpg">The Russian prediction for the continuation of the line of beta stability to the superheavy region</a>.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Beta-decay_stable_isobars">Beta-decay stable isobars</a>.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Isodiapher">Isodiapher</a>.

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Talk:Nuclide#List_of_isodiaphers_that_are_beta-stable">List of beta-stable isodiaphers</a>.

%e a(17) = 1 because the only beta-stable nuclide with neutron excess 17 is 117Sn (Z=50, N=67). Note that neither 113Cd nor 115In is beta-stable.

%e a(22) = 9, with the last three being non-primordial.

%e a(23) = 6 because there are 6 beta-stable nuclides with neutron excess 23: 131Xe, 133Cs, 135Ba, 141Pr, 143Nd and 147Pm.

%e a(24) = 9.

%e a(25) = 5 because there are 5 beta-stable nuclides with neutron excess 25: 137Ba, 139La, 145Nd, 149Sm and 151Eu.

%e a(45) = 5 because there are 5 beta-stable nuclides with neutron excess 45: 213Po, 215At, 217Rn, 219Fr and 221Ra.

%e a(47) = 3 because there are 3 beta-stable nuclides with neutron excess 47: 223Ra, 225Ac and 227Th.

%Y Cf. A368859 (beta-stable isotopes), A368860 (isotones), A318999.

%K nonn,hard,fini

%O -8,8

%A _Jianing Song_, Jan 26 2024