OFFSET
1,1
LINKS
Sean A. Irvine, Table of n, a(n) for n = 1..1000
MATHEMATICA
Select[Union[Flatten[Table[FromDigits[Join[PadRight[{}, n, m], PadRight[{}, k, q]]], {n, 3}, {m, 9}, {k, 3}, {q, {1, 3, 7, 9}}]]], IntegerDigits[#][[1]]!=IntegerDigits[#][[-1]]&&PrimeQ[#]&] (* Harvey P. Dale, Apr 06 2022 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
STATUS
approved