A306991 - OEIS

%I #26 May 23 2019 08:39:29

%S 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,

%T 6,15,10,11,10,8,12,10,12,18,9,12,12,20,14,8,21,15,12,16,10,23,16,21,

%U 12,12,16,18,26,18,20,12,16,18,20,29,12,21,30

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

%C 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, ...

%e 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.

%Y Cf. A298614, A305717, A308222.

%K nonn

%O 1,4

%A _Peter Kagey_, May 18 2019