OFFSET
1,1
MATHEMATICA
fQ[n_] := Union[ MemberQ[ {1, 2, 3, 5, 7}, # ] & /@ (Subtract @@ Sort[ #, Greater] & /@ Subsets[ IntegerDigits@ n, {2}])] == {True} && PrimeQ@ n; Select[ Range@ 4230, fQ]
CROSSREFS
KEYWORD
nonn,base,less
AUTHOR
Robert G. Wilson v, Oct 26 2010
STATUS
approved