|
%I #16 Apr 10 2018 08:28:07
%S 0,1,2,2,2,2,3,2,2,3,2,3,2,3,2,3,2,3,3,2,3,2,3,3,2,3,3,2,3,3,2,3,3,2,
%T 3,3,3,2,3,3,2,3,3,3,2,3,3,3,2,3,3,3,2,3,3,3,2,3,3,3,3,2,3,3,3,2,3,3,
%U 3,3,2,3,3,3,3,2,3,3,3,3,2,3,3,3,3,2,3,3,3,3,3
%N Number of new penny-penny contacts when putting pennies on a table following a spiral pattern.
%H R. W. Grosse-Kunstleve, <a href="http://web.archive.org/web/20050425075654/http://cci.lbl.gov/~rwgk/EIS/PennySpiral.html">Penny Spiral Sequence</a>
%F The n-th "chunk" consists of 2 3{n-2} 2 3{n-1} 2 3{n-1} 2 3{n-1} 2 3{n-1} 2 3{n}, where a{b} symbolizes b repetitions of a.
%e From _Omar E. Pol_, Nov 16 2016: (Start)
%e The sequence written as a spiral begins:
%e .
%e . 2 - 3 - 3 - 3 - 3 - 2
%e . / \
%e . 3 2 - 3 - 3 - 3 - 2 3
%e . / / \ \
%e . 3 3 2 - 3 - 3 - 2 3 3
%e . / / / \ \ \
%e . 3 3 3 2 - 3 - 2 3 3 3
%e . / / / / \ \ \ \
%e . 3 3 3 3 2 - 2 3 3 3 3
%e . / / / / / \ \ \ \ \
%e . 2 2 2 2 2 0 - 1 2 2 2 2
%e . \ \ \ \ \ / / / /
%e . 3 3 3 3 2 - 3 - 2 3 3 3
%e . \ \ \ \ / / /
%e . 3 3 3 2 - 3 - 3 - 2 3 3
%e . \ \ \ / /
%e . 3 3 2 - 3 - 3 - 3 - 2 3
%e . \ \ /
%e . 3 2 - 3 - 3 - 3 - 3 - 2
%e . \
%e . 2 - 3 - 3 - 3 - 3 - 3
%e (End)
%Y Cf. A047932.
%K nonn
%O 1,3
%A _Ralf W. Grosse-Kunstleve_
|
