

A299016


Integer radii of circles over an integer lattice such that the number of unit squares whose centers are contained in the circle is less than the area of the circle.


0



2, 6, 12, 19, 24, 36, 40, 43, 48, 52, 53, 55, 60, 61, 65, 70, 74, 77, 89, 91, 108, 111, 116, 123, 125, 128, 129, 140, 141, 142, 146, 152, 154, 159, 166, 169, 171, 180, 181, 183, 184, 197, 198, 205, 209, 210, 212, 214, 222
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OFFSET

1,1


LINKS

Table of n, a(n) for n=1..49.


EXAMPLE

For the circle with radius a(1) = 2, the point (3/2, 3/2 ), i.e. the center of the unit square bounded by x = 1, x = 2, y = 1, y = 2, is outside the circle of radius 2 centered at the origin so there are 12 unit squares with centers inside the circle of radius 2, and 12 < Pi *2 *2.


MATHEMATICA

t = {}; For[n = 1, n < 223, n++, cnt = 0; For[x = n, x < 0, x++, For[y = n, y < 0, y++, If[N[Norm[{x + 1/2, y + 1/2}]] < n, cnt++]]] If[Pi*n*n > 4*cnt, t = Append[t, n]]] Print[t];


CROSSREFS

Sequence in context: A053660 A104969 A065005 * A347472 A340663 A139084
Adjacent sequences: A299013 A299014 A299015 * A299017 A299018 A299019


KEYWORD

nonn


AUTHOR

Dimitri Papadopoulos, Jun 19 2018


STATUS

approved



