OFFSET
1,1
LINKS
Jinyuan Wang, Table of n, a(n) for n = 1..500
MATHEMATICA
Table[SelectFirst[FromDigits/@Tuples[{7, 8}, n], PrimeQ], {n, 18}]/.Missing[ "NotFound"]->0 (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Oct 07 2018 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Jan 04 1999
STATUS
approved