A070205 Number of acute integer triangles with perimeter n having integral inradius.

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1

Offset

1,84

Comments

a(n) = A070201(n) - A024155(n) - A070206(n).

References

Mohammad K. Azarian, Circumradius and Inradius, Problem S125, Math Horizons, Vol. 15, Issue 4, April 2008, p. 32. Solution published in Vol. 16, Issue 2, November 2008, p. 32.

Links

Table of n, a(n) for n=1..90.

Eric Weisstein's World of Mathematics, Incircle.

Eric Weisstein's World of Mathematics, Acute Triangle.

R. Zumkeller, Integer-sided triangles

Crossrefs

Cf. A070140, A070093.

Sequence in context: A028605 A319532 A317576 * A138363 A080225 A122841

Adjacent sequences: A070202 A070203 A070204 * A070206 A070207 A070208

Keyword

nonn

Author

Reinhard Zumkeller, May 05 2002

Status

approved