Number of conjugacy classes in projective symplectic group of fixed degree over a finite field is PORC function of field size
From Groupprops
Statement
Suppose is an even natural number, i.e., for some natural number . Then, there exists a PORC function of degree such that, for any prime power , the number of conjugacy classes in the projective symplectic group (i.e., the projective symplectic group of degree over the finite field of size ) is .
A PORC function is a polynomial on residue classes  it looks like different polynomial functions on different congruence classes modulo a particular number. In this case, we only need to consider congruence classes modulo to define the PORC function. In fact, for a field size of , the polynomial depends only on the value .
Particular cases
(degree of projective symplectic group)  (degree of PORC function, also number used in Chevalley notation)  Possibilities for  Corresponding congruence classes mod for  Corresponding polynomials in PORC function of giving number of conjugacy classes in  More information  

2  1  2  1 2 
0 1 

See element structure of projective special linear group of degree two over a finite field (note that ). 
4  2  2  1 2 
0 1 

element structure of projective symplectic group of degree four over a finite field 
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