login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A108126 Maximal number of squares of side 1 in an ellipse of semiaxes n,2n. 0
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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 9 04:58 EDT 2021. Contains 343687 sequences. (Running on oeis4.)