A306991 Number of primitive Heronian isosceles triangles with perimeter A308222(n).

1, 1, 1, 2, 2, 3, 2, 2, 3, 3, 5, 4, 3, 6, 4, 4, 5, 4, 8, 6, 9, 6, 6, 4, 8, 11, 8, 10, 6, 9, 9, 8, 14, 6, 15, 10, 11, 10, 8, 12, 10, 12, 18, 9, 12, 12, 20, 14, 8, 21, 15, 12, 16, 10, 23, 16, 21, 12, 12, 16, 18, 26, 18, 20, 12, 16, 18, 20, 29, 12, 21, 30

Offset: 1

Author

Peter Kagey, May 18 2019

Keywords

• nonn

Comments

Records occur at indices of 1, 4, 6, 11, 14, 19, 21, 26, 33, 35, ... corresponding to perimeters of 16, 50, 98, 242, 338, 578, 722, 1058, 1682, 1922, ...

Examples

			For n = 6, the a(6) = 3 primitive Heronian isosceles triangles with perimeter A308222(6) = 98 have side lengths (24,37,37), (25,25,48), and (29,29,40), and areas of 420, 168, and 420 respectively.
		

Crossrefs

Cf. A298614, A305717, A308222.