A054094 T(n,n-2), array T as in A054090.
1, 4, 6, 26, 104, 548, 3366, 24034, 195168, 1777652, 17950550, 199059674, 2405063016, 31448531956, 442501797654, 6666753146498, 107081325959936, 1826636018849444
Offset: 2
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