A295774 a(n) is the minimum size of a restricted planar additive basis for the square [0,2n]^2.

1, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 76, 80, 84, 88, 92

Offset: 0

Author

Jukka Kohonen, Nov 27 2017

Keywords

• nonn
• more

Comments

A planar additive basis for the square [0,2n]^2 is a set of points with nonnegative integer coordinates such that their pairwise sums cover the square. Self-sums are allowed. In a restricted basis all points are in the lower left quadrant [0,n]^2.

Matches A008574 at least up to a(23)=92.

Examples

			a(2)=8: the square [0,4]^2 is covered by the pairwise sums of {(0,0),(1,0),(2,0),(0,1),(2,1),(0,2),(1,2),(2,2)}, which has 8 elements.
		

Links

• J. Kohonen, V. Koivunen and R. Rajamäki, Planar additive bases for rectangles, arXiv preprint arXiv:1711.08812, [math.NT], 2017.
• J. Kohonen, V. Koivunen and R. Rajamäki, Planar additive bases for rectangles, Journal of Integer Sequences, 21 (2018), Article 18.9.8.

Crossrefs

A295771 is the nonrestricted version.