Four couples a are sitting around a round table, in which husband and wife can not be adjacent. How many different seating plans are there?

```
DeleteDuplicatesBy[
DeleteCases[
DeleteCases[
DeleteCases[
DeleteCases[
DeleteDuplicatesBy[
Permutations[Flatten[Table[{h[i], w[i]}, {i, 1, 4}]]],
Cycles@*List], {___, h[a_], w[b_], ___} /; a == b], {___,
w[a_], h[b_], ___} /; a == b], {w[a_], __, h[b_]} /;
a == b], {h[a_], __, w[b_]} /; a == b], Cycles@*List] // Length
```

The result of my calculation according to the above method is `11904`

, but the reference answer is `1488`

. I want to know where I made a mistake in my calculation.

**Examples of correct answers:**

```
DeleteCases[
DeleteCases[
Prepend[#, "a"[1]] & /@
Permutations[
Flatten[Table[Array[i, 2], {i, Alphabet[][[1 ;; 4]]}]] //
Rest], {___, x_[_], x_[_], ___}], {x_[_], __, x_[_]}] // Length
```