%I A018226
%S A018226 2,8,20,28,50,82,126
%N A018226 Magic numbers: atoms with one of these numbers of protons or neutrons 
               in their nuclei are considered to be stable.
%C A018226 A Google search on `"2,8,20,28,50" Magic number` will turn up hundreds 
               of other links.
%C A018226 First seven positive terms of A162626, the magic sequence. [From Omar 
               E. Pol (info(AT)polprimos.com), Jul 07 2009]
%D A018226 A brief description is given under "Magic numbers" in the Encyclopedia 
               Britannica.
%D A018226 S. Bjornholm, Clusters..., Contemp. Phys. 31 1990 pp. 309-324 (p. 312).
%D A018226 Dictionary of Science (Simon and Schuster), see the entry for "Magic 
               number".
%D A018226 J. Fridmann et al., 'Magic' nucleus 42-Si, Nature, 435 (2005), 922-924 
               and 897-898.
%D A018226 J. Glanz, Uut and Uup Add Their Atomic Mass to Periodic Table, New York 
               Times, Feb 01, 2003, pages 1 and 26.
%D A018226 R. V. F. Janssens, Unexpected doubly magic nucleus, Nature, 459 (jun 
               25 2009), 1069-1070. _Added by N. J. A. Sloane, Jul 05 2009]
%D A018226 D. Warner, Not-so-magic numbers, Nature, 430 (Jul 29 2004), 517-519.
%H A018226 Radoslav Jovanovic, <a href="http://milan.milanovic.org/math/english/
               atom/proton.html">Magic Numbers and the Pascal Triangle</a>
%H A018226 V. Ladma, <a href="http://www.sweb.cz/vladimir_ladma/english/notes/texts/
               magicn.htm">Magic Numbers</a>
%H A018226 NAPC Isotope Hudrology Section, <a href="http://www.iaea.or.at/programmes/
               ripc/ih/volumes/vol_one/cht_i_02.pdf">Chapter 2, Atomic Systematics 
               and Nuclear Structure</a>
%H A018226 D. Weise, <a href="http://www.mi.sanu.ac.yu/vismath/weise1/">The Pythagorean 
               Approach to Problems of Periodicity in Chemistry and Nuclear Physics"</
               a>
%F A018226 If n is prime and nearest-neighbor of a prime then a(n)=n(n+1)(n+2)/3 
               else a(n)=n(n^2+5)/3, where 0<n<8. [From Omar E. Pol (info(AT)polprimos.com), 
               Jul 07 2009]
%p A018226 Contribution from Omar E. Pol (info(AT)polprimos.com), Jul 07 2009: (Start)
%p A018226 For n=1 to 7
%p A018226 If n=2 or n=3 then a(n)=n(n+1)(n+2)/3 else a(n)=n(n^2+5)/3
%p A018226 next n
%p A018226 (End)
%Y A018226 Cf. A018227, A033547, A110856.
%Y A018226 Cf. A130598, A162626. [From Omar E. Pol (info(AT)polprimos.com), Jul 
               07 2009]
%Y A018226 Sequence in context: A136904 A043002 A108180 this_sequence A162626 A137306 
               A110856
%Y A018226 Adjacent sequences: A018223 A018224 A018225 this_sequence A018227 A018228 
               A018229
%K A018226 nonn,fini,full
%O A018226 1,1
%A A018226 John Raithel (raithel(AT)rahul.net)