The symbol for a majority of elements in the periodic table comprises two English alphabets with the first letter written as a capital and the second letter written in lowercase.
For example, Na (Sodium)
However, for the above example, if the sequence of alphabets is reversed (i.e. An), the new symbol 'An' does not belong to any element in the present periodic table containing 118 elements.
Make a comprehensive list of all such symbol pairs where both arrangements (Pq type as well as Qp type) represent the symbol of an existing element. For example, Al and La (Aluminium and Lanthanum)
The pairs of the element are as follows: