A331042 a(n) = 4 * squared radius of inscribed circles of triangles with integer sides i <= j <= k, such that the number of triangles with this radius sets a new record. If this radius is not a multiple of (1/4), a(n) = 0.

0, 0, 3, 7, 12, 15, 32, 35, 55, 63, 95, 119, 135, 224, 231, 255, 320, 351, 455, 495, 855, 864, 896, 1071, 1440

Offset: 1

Author

Hugo Pfoertner, Jan 11 2020

Keywords

• nonn
• more

Comments

It is conjectured that all radii of incircles leading to records with the exception of the first two terms are multiples of 1/4, thus a(n) > 0 for all n > 2.

See A331040 for more information and examples.

Crossrefs

Cf. A120062, A331012.

Cf. A331040, A331041, A331043 (records of numbers of triangles).

Formula

If A331041(n) equals 1 or 4, a(n) = 4 * A331040(n)/A331041(n), 0 otherwise.