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%I #10 Jan 03 2015 09:10:20
%S 1,5,7,9,13,14,18,25,29,33,35,39,43,45,49,51,55,57,59,63,69,73,77,79,
%T 83,89,93,97,99,101,103,107,109,113,117,121,123,127,129,133,134,136,
%U 140,144,146,158,160,164,165,169,173,177,181,183,187
%N Circular disk sequence for the lattice of the Archimedean tiling (3,4,6,4).
%C For the squares of the radii of the lattice point hitting circles of the Archimedean tiling (3,4,6,4) see A249870 and A249871.
%C The first differences for this sequence are given in A251628.
%H Wolfdieter Lang, <a href="/A251627/a251627_1.pdf">On lattice point circles for the Archimedean tiling (3,4,6,4) </a>
%F a(n) is the number of lattice points of the Archimedean tiling (3,4,6,4) on the boundary and the interior of the circular disk belonging to the radius R(n) = sqrt(A249870(n) + A249871(n)* sqrt(3)), for n >= 0.
%e n=4: The radius of the disk is R(4) = sqrt(2 + sqrt(3)), approximately 1.932. The lattice points for this R(n)-disk are the origin, four points on the circle with radius R(1) = 1, two points on the circle with radius R(2) = sqrt(2), two points on the circle with radius R(3) = sqrt(3) and 4 points on the circle with radius R(4) = sqrt(2+sqrt(3)), all together 1 + 4 + 2 + 2 + 4 = 13 = a(4) lattice points. See Figure 3 of the note given in the link.
%Y Cf. A249870, A249871, A251628.
%K nonn,easy
%O 0,2
%A _Wolfdieter Lang_, Dec 09 2014
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