OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..43
MATHEMATICA
Select[ FromDigits /@ Flatten[ Table[ PadRight[{5}, i, # ] & /@ {1, 2, 3, 4, 5, 6, 7, 8, 9}, {i, 2, 24}], 1], PrimeQ[ # ] &]
Join[{5}, Select[Flatten[Table[FromDigits[PadRight[{5}, n, k]], {n, 2, 20}, {k, {1, 3, 7, 9}}]], PrimeQ]] (* Harvey P. Dale, May 31 2020 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Robert G. Wilson v, Nov 22 2003
STATUS
approved