The formula provided is a valid method to validate PAN in Excel. The formula checks if the length of the PAN is 10, the first 5 characters are text, the next 4 characters are numbers, and the last character is text. The formula is:

=AND(LEN(A1)=10,SUMPRODUCT(--(--(ISNUMBER(MID(A1,{1,2,3,4,5,6,7,8,9,10},1)+0))={0, 0,0,0,0,1,1,1,1,0}))+SUMPRODUCT(--(CODE(MID(UPPER(A1),{1,2,3,4,5,10},1))>64))=16)

The formula uses the AND function to check if all the conditions are met. The LEN function checks if the length of the PAN is 10. The SUMPRODUCT function checks if the first 5 characters are text and the next 4 characters are numbers. The CODE function converts the last character to its ASCII code and checks if it is a text character. The formula returns TRUE if all the conditions are met and FALSE otherwise.

I hope this helps!