A320310 (1/4) * number of ways to select 3 distinct points forming a triangle of unsigned area = n/2 from a square of grid points with side length n.

1, 8, 23, 82, 114, 416, 373, 1149, 1351, 2598, 2113, 7158, 4094, 9344, 11528, 18243, 11882, 33006, 18603, 48760, 42102, 54312, 40061, 121728, 68115, 105204, 112546, 178322, 101798, 284980, 133229, 300367, 247900, 305062, 295972, 625544, 271864, 475004, 479658, 847208

Offset

1,2

Comments

Permutations of the 3 points are not counted separately.

Links

Giovanni Resta, Table of n, a(n) for n = 1..100

Crossrefs

Cf. A115004, A320540, A320542, A320544.

Sequence in context: A099274 A208633 A036562 * A303720 A304414 A305949

Adjacent sequences: A320307 A320308 A320309 * A320311 A320312 A320313

Keyword

nonn

Author

Hugo Pfoertner, Oct 23 2018

Extensions

a(35)-a(40) from Giovanni Resta, Oct 26 2018

Status

approved