A130556 - OEIS

%I #2 Mar 31 2012 20:55:21

%S 1,11,1,111,1,11,1111,11,1,111,11111,111,1,11,1111,111111,1111,11,1,

%T 111,11111,1111111,11111,111,1,11,1111,111111,11111111,111111,1111,11,

%U 1,111,11111,1111111

%N A model of the atomic nucleus (Shell model of nucleus). A triangle.

%C 1 is equal to 2 protons, 11 is equal to 2+2 protons, 111 is equal to 2+2+2 protons...

%C Repunit numbers represent the subshells.

%e A geometric model of the shell structure of nucleus:

%e ...|----------------------.i.----------------------|

%e ...|...|------------------.h.------------------|...|

%e ...|...|...|--------------.g.--------------|...|...|

%e ...|...|...|...|----------.f.----------|...|...|...|

%e ...|...|...|...|...|------.d.------|...|...|...|...|

%e ...|...|...|...|...|...|--.p.--|...|...|...|...|...|

%e ...|...|...|...|...|...|...s...|...|...|...|...|...|

%e ...|...|...|...|...|...|...|...|...|...|...|...|...|

%e ...|...|...|...|...|...|.......|...|...|...|...|...|

%e ...|...|...|...|...|.......1.......|...|...|...|...|

%e ...|...|...|...|......11.......1.......|...|...|...|

%e ...|...|...|......111......1......11.......|...|...|

%e ...|...|.....1111.....11.......1......111......|...|

%e ...|.....11111....111......1......11.....1111......|

%e ....111111...1111.....11.......1......111....11111....

%e 1111111..11111....111......1......11.....1111...111111

%e ......................................................

%e ...|...|...|...|...|...|...|...|...|...|...|...|...|

%e ...|...|...|...|...|...|...|1/2|...|...|...|...|...|

%e ...|...|...|...|...|...|----3/2----|...|...|...|...|

%e ...|...|...|...|...|--------5/2--------|...|...|...|

%e ...|...|...|...|------------7/2------------|...|...|

%e ...|...|...|----------------9/2----------------|...|

%e ...|...|-------------------11/2--------------------|

%e ...|----------------------.13/2.--------------------

%Y Cf. A056951, A130517, A130598, A130602.

%K nonn,tabl

%O 1,2

%A _Omar E. Pol_, Aug 09 2007, Aug 12 2007