A070141 Number of obtuse integer triangles with perimeter n having integral area.

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, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 3, 0, 0, 0, 0, 0, 1, 0, 0, 0, 3, 0, 1, 0, 0, 0, 0, 0, 3, 0, 0, 0, 1, 0, 1, 0, 2, 0, 0, 0, 4, 0, 0, 0, 1, 0, 2

Offset

1,36

Comments

a(n) = A051516(n) - A070140(n) - A024155(n).

Links

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

Eric Weisstein's World of Mathematics, Heronian Triangle.

Eric Weisstein's World of Mathematics, Obtuse Triangle.

R. Zumkeller, Integer-sided triangles

Crossrefs

Cf. A051516, A070101, A070147.

Sequence in context: A082786 A101638 A321379 * A088722 A336917 A122180

Adjacent sequences: A070138 A070139 A070140 * A070142 A070143 A070144

Keyword

nonn

Author

Reinhard Zumkeller, May 05 2002

Status

approved