Tricky numbering formula

[Penpen22]

I have the columns "ID" and "Name".

I want to generate an ID for every row but only for each different name so something like this:

<table cellpadding="2.5px" rules="all" style=";background-color: #FFFFFF;border: 1px solid;border-collapse: collapse; border-color: #BBB"><colgroup><col width="25px" style="background-color: #DAE7F5" /><col /><col /></colgroup><thead><tr style=" background-color: #DAE7F5;text-align: center;color: #161120"><th width="22"> ID Number</th><th width="70">Name</th></tr></thead><tbody><tr ><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">1</td><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">Adam</td></tr><tr ><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">2</td><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">Alice</td></tr><tr ><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">2</td><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">Alice</td></tr><tr ><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">3</td><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">Brian</td></tr><tr ><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">4</td><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">Chloe</td></tr><tr ><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">4</td><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">Chloe</td></tr><tr ><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">4</td><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">Chloe</td></tr><tr ><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">5</td><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">Darren</td></tr><tr ><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">6</td><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">Evan</td></tr><tr ><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">6</td><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">Evan</td></tr><tr ><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">7</td><td style="border-top: 1px solid black;border-right: 1px solid black;border-bottom: 1px solid black;border-left: 1px solid black;;">Fiona</td></tr></tbody></table>

Any ideas?

 

[Marcelo Branco]

Formula in A2
=IF(COUNTIF($B$2:B2,B2)=1,MAX($A$1:A1)+1,A1)

copy down

M.

 

[Penpen22]

That works great, thank you!