How to calculate EAN VALUE ? And also explain the stability criteria with respect to EAN value

EFFECTIVE ATOMIC NUMBER (EAN) 
 
• The sum of the number of electrons, donated by all ligands and those present on the central metal ion or atom in complex is called as effective atomic number (EAN).

• Generally EAN of central metal ion will be equal to the number of electrons in the nearest noble gas.

• If the EAN of the central metal is equal to the number of electrons in the nearest noble gas then the complex possess greater stability.

EAN = [(atomic number of central metal) – (the oxidation state of the metal) + (the number of electrons gained by the metal from the ligands through co-ordination)]

EAN= [Z metal – (ox.state of the metal) + 2(coordination number of the metal)].

for example. 
[Co(NH3)6]3+ →EAN = [27 – 3 + 2(6)] = 36