OFFSET
1,1
COMMENTS
Potential candidates for A224929.
Subsequence of A002476. - Michel Marcus, May 06 2014
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..10000
MATHEMATICA
Select[ Prime@ Range@ 1250, Union@ Join[{1, 3, 7, 9}, IntegerDigits@#] == {1, 3, 7, 9} && Mod[#, 3] == 1 &]
Select[Flatten[Table[FromDigits/@Tuples[{1, 3, 7, 9}, n], {n, 4}]], PrimeQ[#] && Mod[#, 3]==1&] (* Harvey P. Dale, Jun 16 2017 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Robert G. Wilson v, May 06 2014
STATUS
approved