Formula: Count of Unique 'Afhaalpunt' for this 'Artikel_Nr'

[Roy_Excel_Island_Apps]

Hi, can someone help me to find the formula that I can fill out in column C to count all unique Shop_ID's per Article_ID?

	A	B	C
1	Shop_ID	Article_ID	Count of Unique Shop_ID's for the linked Article_ID
2	205	15789	Result has to be '4'
3	55	43187
4	206	15789
5	205	15789	(This is a double one with the first record, so don't count it)
6	55	43187
7	44	43187
8	55	15789
9	44	43187
10	95	15789

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Thanks !

Roy

 

[Roy_Excel_Island_Apps]

It looks like its working but still taking a long time. He's also recalculating with every single click in the sheet so I will try to copy/paste as values after the execution. It will be processed in a batch so I hope we can solve it this way. Thanks for your help!