A027162 a(n) = T(2n-1,n-2), T given by A027157.
4, 15, 112, 440, 3328, 13552, 103168, 429696, 3282944, 13882880, 106307584, 454471680, 3485499392, 15022878720, 115345653760, 500317061120, 3844727111680, 16761479102464, 128891635105792, 564250624917504, 4341301000536064
Offset: 2