A197458 -id:A197458 - cp's OEIS frontend

A279454 Number of nonequivalent ways to place k>=0 points on an n X n square grid so that no more than 2 points are on a vertical or horizontal straight line.

Original entry on oeis.org

2, 6, 54, 1026, 38931, 2198241, 167110761, 16248457762, 1960813221768

Offset: 1

Heinrich Ludwig, Dec 24 2016

Row sum of triangle A279453.

Rotations and reflections of a placement are not counted. For numbers if they are to be counted, see A197458.

Cf. A197458, A279453.

A283500 Triangle read by rows: T(n,k) = number of n X n (0,1) matrices with at most k 1's in each row or column.

Original entry on oeis.org

2, 7, 16, 34, 265, 512, 209, 7343, 41503, 65536, 1546, 304186, 6474726, 24997921, 33554432, 13327, 17525812, 1709852332, 21252557377, 57366997447, 68719476736, 130922, 1336221251, 702998475376, 34215495252681, 252540841305558, 505874809287625

Offset: 1

R. J. Mathar, Mar 09 2017

			Triangle begins:
2;
7,     16;
34,    265,      512;
209,   7343,     41503,      65536;
1546,  304186,   6474726,    24997921,    33554432;
13327, 17525812, 1709852332, 21252557377, 57366997447, 68719476736;
...

Andrew Howroyd, Table of n, a(n) for n = 1..84

Cf. A002720 (column k=1), A197458 (column k=2), A008300 (exactly k 1s).
Main diagonal and first lower diagonal give: A002416, A048291.
Cf. A247158 (k=n/2).

cp's OEIS Frontend

A279454 Number of nonequivalent ways to place k>=0 points on an n X n square grid so that no more than 2 points are on a vertical or horizontal straight line.

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A283500 Triangle read by rows: T(n,k) = number of n X n (0,1) matrices with at most k 1's in each row or column.

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