A130556 A model of the atomic nucleus (Shell model of nucleus). A triangle.

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

Offset

1,2

Comments

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

Repunit numbers represent the subshells.

Links

Table of n, a(n) for n=1..36.

Example

A geometric model of the shell structure of nucleus:
...|----------------------.i.----------------------|
...|...|------------------.h.------------------|...|
...|...|...|--------------.g.--------------|...|...|
...|...|...|...|----------.f.----------|...|...|...|
...|...|...|...|...|------.d.------|...|...|...|...|
...|...|...|...|...|...|--.p.--|...|...|...|...|...|
...|...|...|...|...|...|...s...|...|...|...|...|...|
...|...|...|...|...|...|...|...|...|...|...|...|...|
...|...|...|...|...|...|.......|...|...|...|...|...|
...|...|...|...|...|.......1.......|...|...|...|...|
...|...|...|...|......11.......1.......|...|...|...|
...|...|...|......111......1......11.......|...|...|
...|...|.....1111.....11.......1......111......|...|
...|.....11111....111......1......11.....1111......|
....111111...1111.....11.......1......111....11111....
1111111..11111....111......1......11.....1111...111111
......................................................
...|...|...|...|...|...|...|...|...|...|...|...|...|
...|...|...|...|...|...|...|1/2|...|...|...|...|...|
...|...|...|...|...|...|----3/2----|...|...|...|...|
...|...|...|...|...|--------5/2--------|...|...|...|
...|...|...|...|------------7/2------------|...|...|
...|...|...|----------------9/2----------------|...|
...|...|-------------------11/2--------------------|
...|----------------------.13/2.--------------------

Crossrefs

Cf. A056951, A130517, A130598, A130602.

Sequence in context: A104490 A164851 A038713 * A277932 A290676 A290420

Adjacent sequences: A130553 A130554 A130555 * A130557 A130558 A130559

Keyword

nonn,tabl

Author

Omar E. Pol, Aug 09 2007, Aug 12 2007

Status

approved