O ( a b , c )  Π ( a , b )   = ( n − 1 ) μ ( a ) ( I { a = c }   + I { b = c }   )       ( 62 )   MathType@MTEF@5@5@+=feaafiart1ev1aaatCvAUfKttLearuWrP9MDH5MBPbIqV92AaeXatLxBI9gBaebbnrfifHhDYfgasaacH8akY=wiFfYdH8Gipec8Eeeu0xXdbba9frFj0=OqFfea0dXdd9vqai=hGuQ8kuc9pgc9s8qqaq=dirpe0xb9q8qiLsFr0=vr0=vr0dc8meaabaqaciaacaGaaeqabaqabeGadaaakeaadaWcaaqaaGqabiab=9eapjabcIcaOiabdggaHjabdkgaIjabcYcaSiabdogaJjabcMcaPaqaaiabfc6aqjabcIcaOiabdggaHjabcYcaSiabdkgaIjabcMcaPaaacqGH9aqpcqGGOaakcqWGUbGBcqGHsislcqaIXaqmcqGGPaqkiiGacqGF8oqBcqGGOaakcqWGHbqycqGGPaqkcqGGOaaktuuDJXwAK1uy0HMmaeHbfv3ySLgzG0uy0HgiuD3BaGabaiab9Hi8jnaaBaaaleaacqGG7bWEcqWGHbqycqGH9aqpcqWGJbWycqGG9bqFaeqaaOGaey4kaSIae0hIWN0aaSbaaSqaaiabcUha7jabdkgaIjabg2da9iabdogaJjabc2ha9bqabaGccqGGPaqkcaWLjaGaaCzcaiabcIcaOiabiAda2iabikdaYiabcMcaPaaa@690B@