|
Search: id:A122225
|
|
|
| A122225 |
|
(1/4)*number of non-square rectangles with corners on an n X n grid of points. |
|
+0
1
|
|
| 1, 6, 20, 52, 111, 214, 376, 620, 967, 1452, 2096, 2952, 4047, 5422, 7128, 9236, 11773, 14834, 18450, 22704, 27675, 33460, 40090, 47708, 56383, 66214, 77276, 89748, 103647, 119206, 136476, 155592, 176681, 199858, 225224, 253104, 283555, 316692
(list; graph; listen)
|
|
|
OFFSET
|
3,2
|
|
|
LINKS
|
Jon Schoenfield, Table of n, a(n) for n = 3..500
Jon Schoenfield, QBasic program
|
|
EXAMPLE
|
a(3)=1 because there are 4 rectangles that can be formed on the square grid [0,1,2] X [0,1,2]: {(0 0),(0 1),(2 0),(2 1)}, {(0 0),(0 2),(1 0),(1 2)}, {(0 1),(0 2),(2 1),(2 2)}, {(1 0),(1 2),(2 0),(2 2)}.
|
|
CROSSREFS
|
Cf. A000537, A085582, A113751.
Sequence in context: A067117 A119365 A001211 this_sequence A027178 A055909 A036596
Adjacent sequences: A122222 A122223 A122224 this_sequence A122226 A122227 A122228
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Hugo Pfoertner (hugo(AT)pfoertner.org), Sep 29 2006
|
|
EXTENSIONS
|
Corrected and extended by Jon E. Schoenfield (jonscho(AT)hiwaay.net), Oct 08 2006
|
|
|
Search completed in 0.002 seconds
|
