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A235458 Number of non-equivalent (mod D_4) ways to arrange 7 points on an n X n square grid so that no three points are collinear. 6
28, 3385, 134353, 1958674, 19929645, 138586349, 753795278, 3356614240, 13108210508, 44374441652, 137349454120 (list; graph; refs; listen; history; text; internal format)
OFFSET
4,1
COMMENTS
Column 7 of A235453.
Without the restriction "non-equivalent (mod D_4)" the numbers are given by A194192, n >= 4.
LINKS
EXAMPLE
There are a(4) = 28 non-equivalent ways to place 7 points (X) on a 4 X 4 grid. Example:
. X X .
. . . X
X . . X
X X . .
CROSSREFS
Cf. A235453, A194192, A235454 (3 points), A235455 (4 points), A235456 (5 points), A235457 (6 points).
Sequence in context: A285151 A232520 A061787 * A128506 A164655 A291585
KEYWORD
nonn,more
AUTHOR
Heinrich Ludwig, Jan 12 2014
EXTENSIONS
a(13), a(14) from Heinrich Ludwig, Nov 16 2016
STATUS
approved

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Last modified June 14 04:49 EDT 2024. Contains 373393 sequences. (Running on oeis4.)