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!)
A267710 Number of unit triangular lattice cells enclosed by origin centered circle of diameter n. 2
0, 6, 6, 24, 24, 54, 60, 96, 114, 150, 180, 216, 258, 324, 348, 426, 450, 540, 564, 666, 720, 804, 870, 954, 1056, 1134, 1230, 1344, 1416, 1542, 1614, 1752, 1842, 1974, 2100, 2208, 2346, 2478, 2628, 2778, 2898, 3084, 3180, 3378, 3474, 3684, 3822, 4002, 4176, 4356 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

As n -> infinity, lim a(n)/(n^2) -> Pi/sqrt(3).

LINKS

Luca Petrone, Table of n, a(n) for n = 1..200

CROSSREFS

Cf. A093602 (Pi/sqrt(3)).

Sequence in context: A253100 A247640 A255470 * A306896 A087236 A219910

Adjacent sequences:  A267707 A267708 A267709 * A267711 A267712 A267713

KEYWORD

easy,nonn

AUTHOR

Luca Petrone, Jan 19 2016

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 August 11 23:45 EDT 2020. Contains 336434 sequences. (Running on oeis4.)