For each single digit {0,1,...,9} record the smallest prime made up of copies of that digit (if there is one); repeat for all of the C(10,2) = 45 pairs of distinct decimal digits; then for all triples; etc.

A099756

For each single digit {0,1,...,9} record the smallest prime made up of copies of that digit (if there is one); repeat for all of the C(10,2) = 45 pairs of distinct decimal digits; then for all triples; etc.