A251628 - OEIS

A251628

Number of lattice points of the Archimedean tiling (3,4,6,4) on the circles R(n) = sqrt(A249870(n) + A249871(n)* sqrt(3)) around any lattice point. First differences of A251627.

1, 4, 2, 2, 4, 1, 4, 7, 4, 4, 2, 4, 4, 2, 4, 2, 4, 2, 2, 4, 6, 4, 4, 2, 4, 6, 4, 4, 2, 2, 2, 4, 2, 4, 4, 4, 2, 4, 2, 4, 1, 2, 4, 4, 2, 12, 2, 4, 1, 4, 4, 4, 4, 2, 4, 2, 4, 6, 4, 4, 2, 2, 2, 4, 2, 2, 4, 4, 4, 4, 4, 4, 4, 2, 2, 2, 6, 4, 2, 4, 4

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OFFSET

0,2

COMMENTS

The squares of the increasing radii of the lattice point hitting circles for the Archimedean tiling (3,4,6,4) are given in A249870 and A249871.

See the notes given in a link under A251627.

LINKS

Table of n, a(n) for n=0..80.

FORMULA

a(n) = A251627(n) - A251627(n-1), for n >= 1 and a(0) = 1.

EXAMPLE

n = 4: on the circle with R(4) = sqrt(2 + sqrt(3)), approximately 1.932, around any lattice point lie a(4) = 4 points, namely in Cartesian coordinates, [+/-(1 + sqrt(3)/2), 1/2] and [+/-(1/2), -(1 + sqrt(3)/2)].

CROSSREFS

Cf. A249870, A249871, A251627.

Sequence in context: A275745 A053879 A216671 * A170988 A141035 A082129

Adjacent sequences: A251625 A251626 A251627 * A251629 A251630 A251631

KEYWORD

nonn,easy

AUTHOR

Wolfdieter Lang, Dec 09 2014

STATUS

approved