A095288 Least middle side of 2^n primitive arithmetic triangles, i.e., primitive Heronian triangles whose sides are in arithmetic progression.

4, 28, 364, 6916, 214396, 7932652, 341104036, 20807346196, 1394092195132, 101768730244636, 8039729689326244, 779853779864645668, 80324939326058503804, 8755418386540376914636, 1111938135090627868158772

Offset: 0

Author

Lekraj Beedassy, Jul 02 2004

Keywords

• nonn

Examples

			6916 is the first middle side belonging to 2^3=8 arithmetic triangles, viz., (3485,6916,10347), (3747,6916,10085), (4133,6916,9699), (4299,6916,9533), (4827,6916,9005), (5045,6916,8787), (5333,6916,8499), (6267,6916,7565) of common differences 3431, 3169, 2783, 2617, 2089, 1871, 1583, 649 respectively and integral areas. (Perimeter is obviously three times middle side and hence the same for all the triangles.)
		

Crossrefs

Cf. A086909.

Formula

a(n) = A095267(n)/3 = a(n-1) * A002476(n). - Ray Chandler, Jul 09 2004

Extensions

More terms from Ray Chandler, Jul 09 2004