=ISNUMBER(MATCH(I3;INDEX(marke****ch;0;1);0))+0

or

=1-ISNA(VLOOKUP(I3;marke****ch;1;0))

1 as result means a hit, and 0 a failure.

carl wrote:
I use this formula:

=VLOOKUP(I3;marke****ch;1;FALSE)

Can it be modified to not return #N/A ?

Thank you in advance.

--

[1] The SumProduct function should implicitly coerce the truth values to
their Excel numeric equivalents.
[2] The lookup functions should have an optional argument for the return
value, defaulting to #N/A in its absence.