1. An apparatus, comprising: an array of memory cells; and periphery logic coupled to the array, the periphery logic being configured to generate indices for respective set digits of a mask comprising a plurality of digits, wherein generating the indices comprises: generating an indicator mask by resetting, in response to a first control signal, a second set digit of the mask different from a first set digit of the mask; and converting, in response to a second control signal, a digit position of the first set digit in the indicator mask to an identifier value as an index; and wherein set digits of the mask indicate columns of the array having a particular attribute.