OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
S1[1] := {1}: S3[1]:= {3}: S7[1]:= {7}:
S13[1]:= {}: S17[1]:= {}: S37[1]:={}:
S137[1]:= {}:
for n from 2 to 5 do
S1[n]:= map(t -> 10*t+1, S1[n-1]);
S3[n]:= map(t -> 10*t+3, S3[n-1]);
S7[n]:= map(t -> 10*t+7, S7[n-1]);
S13[n]:= map(t -> 10*t+1, S13[n-1] union S3[n-1]) union
map(t -> 10*t+3, S13[n-1] union S1[n-1]);
S17[n]:= map(t -> 10*t+1, S17[n-1] union S7[n-1]) union
map(t -> 10*t+7, S17[n-1] union S1[n-1]);
S37[n]:= map(t -> 10*t+3, S37[n-1] union S7[n-1]) union
map(t -> 10*t+7, S37[n-1] union S3[n-1]);
S137[n]:= map(t -> 10*t+1, S137[n-1] union S37[n-1]) union
map(t -> 10*t+3, S137[n-1] union S17[n-1]) union
map(t -> 10*t+7, S137[n-1] union S13[n-1]);
od:
sort(convert(`union`(seq(select(isprime, S137[n]), n=3..5)), list)); # Robert Israel, Jan 16 2019
MATHEMATICA
Select[Prime[Range[7300]], Union[IntegerDigits[#]]=={1, 3, 7}&] (* Harvey P. Dale, Jun 11 2013 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Rick L. Shepherd, Jun 01 2005
STATUS
approved