A026882 T(2n,n-3), T given by A026769.
1, 14, 127, 956, 6512, 41786, 258077, 1553610, 9188078, 53657836, 310517294, 1785024568, 10211000720, 58198617436, 330817445679, 1876740925932, 10631509031932, 60164430240578, 340233944451908, 1923162599240162
Offset: 3