For a 6-cell row, only 14 arrangements are valid.
Two symmetries apply to every row: complement (swap ↔) and reversal (read right-to-left). Under both, the 14 rows collapse into 5 equivalence classes.
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↔ {1, 14}
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↔ {4, 11} (alternating)
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↔ {6, 9}
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↔ {2, 3, 12, 13}
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↔ {5, 7, 8, 10}
Three classes (A, B, C) have size 2 (complement and reversal produce the same row). Two classes (D, E) have size 4 (complement and reversal produce four distinct rows).