A362014 - OEIS

A362014

Number of distinct lines passing through exactly two points in a triangular grid of side n.

0, 0, 3, 6, 18, 39, 81, 141, 237, 369, 561, 801, 1119, 1521, 2043, 2667, 3429, 4329, 5415, 6675, 8163, 9879, 11877, 14127, 16695, 19593, 22881, 26523, 30591, 35085, 40089, 45591, 51681, 58359, 65715, 73701, 82389, 91791, 102015, 113007, 124875

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OFFSET

0,3

REFERENCES

Samuel Dittmer, Hiram Golze, Grant Molnar, and Caleb Stanford, Puzzle and Proof: A Decade of Problems from the Utah Math Olympiad, CRC Press, 2025, p. 34.

LINKS

Table of n, a(n) for n=0..40.

FORMULA

a(n) = A244504(n) - A234248(n). - Andrew Howroyd, Apr 03 2023

CROSSREFS

Cf. A234248, A244504 (lines which contain 2 or more points), A050534 (total number of pairs of points). Both are upper bounds.

Sequence in context: A026532 A160505 A081150 * A216813 A356766 A181037

Adjacent sequences: A362011 A362012 A362013 * A362015 A362016 A362017

KEYWORD

nonn

AUTHOR

Caleb Stanford, Apr 03 2023

STATUS

approved