A026111 a(n) = T(2n-1,n), where T is the array defined in A026105.
3, 16, 89, 496, 2795, 15884, 90909, 523312, 3026850, 17577660, 102425257, 598575368, 3506930635, 20591787300, 121145018325, 713948286528, 4214030403902, 24907512574608, 147403116947718
Offset: 2