A026072 a(n) = T(2n-1,n), where T is the array defined in A024996.
1, 3, 13, 76, 427, 2427, 13871, 79729, 460473, 2670394, 15540822, 90717305, 530946697, 3114680815, 18308774295, 107817336510, 635942014275, 3756423495198, 22217666030882, 131563775350068
Offset: 1