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

1,3

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.

Links

Table of n, a(n) for n=1..25.

Formula

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

Crossrefs

Cf. A120062, A331012.

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

Sequence in context: A096998 A356353 A317307 * A122981 A122982 A101589

Adjacent sequences: A331039 A331040 A331041 * A331043 A331044 A331045

Keyword

nonn,more

Author

Hugo Pfoertner, Jan 11 2020

Status

approved