A070202 Number of integer triangles with perimeter n, integer inradius and side lengths that are not relatively prime.

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, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 2, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 3, 0, 0, 0, 1, 0, 1

Offset: 1

Author

Reinhard Zumkeller, May 05 2002

Keywords

• nonn

Examples

			For perimeter 24, only the triangle with a=6, b=8, c=10 has an integer inradius (2), therefore a(24)=1. The next examples are a(32)=1 with a=10, b=10, c=12 and a(36)=1 with a=9, b=12, c=15.
		

Links

• Eric Weisstein's World of Mathematics, Incircle.
• Reinhard Zumkeller, Integer-sided triangles

Crossrefs

Cf. A070138, A051493, A070109, A070209.

Extensions

Definition corrected by Georg Fischer, Apr 04 2024