A026332 a(n) = T(2n,n), where T is the array in A026323.
1, 2, 10, 50, 266, 1452, 8073, 45460, 258434, 1479986, 8525205, 49342636, 286721450, 1671668520, 9774222930, 57291319170, 336537958394, 1980643375180, 11676498649312, 68940592625476, 407593403738856, 2412749904577020
Offset: 0