A108126 - OEIS

A108126

Maximal number of squares of side 1 in an ellipse of semiaxes n,2n.

3, 17, 43, 83, 137, 203, 279, 369, 471, 587, 715, 857, 1011, 1175, 1351, 1541, 1743, 1961, 2191, 2429, 2683, 2949, 3227, 3523, 3829, 4137, 4469, 4809, 5167, 5539, 5913, 6295, 6701, 7127, 7555, 7999, 8449, 8909, 9395, 9889, 10395, 10915

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..42.

EXAMPLE

a(1)=3 since you cannot pack more than 3 unit-side squares in an ellipse of semiaxes 1,2

MATHEMATICA

f[n_] := 2 Sum[IntegerPart[2 Sqrt[4 n^2 - (h - 1/2)^2]],

{h, 2, 2 n}] + IntegerPart[2 Sqrt[4 n^2 - 1/4]]; Array[f, 42]

CROSSREFS

Similar to A125228.

Sequence in context: A092347 A215429 A126587 * A106256 A091624 A106078

Adjacent sequences: A108123 A108124 A108125 * A108127 A108128 A108129

KEYWORD

easy,nonn

AUTHOR

Pasquale CUTOLO (p.cutolo(AT)inwind.it), Jun 14 2007

STATUS

approved