OFFSET
1,1
LINKS
Jinyuan Wang, Table of n, a(n) for n = 1..1000
MATHEMATICA
Flatten[Table[Select[FromDigits/@Tuples[{1, 7}, n], PrimeQ, 1], {n, 25}]/.{}->{0}] (* Jinyuan Wang, Mar 09 2020 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Jan 04 1999
EXTENSIONS
a(16) corrected by Jinyuan Wang, Mar 09 2020
STATUS
approved