OFFSET
1,1
COMMENTS
The next term (a(11)) has 163 digits. - Harvey P. Dale, Mar 23 2023
LINKS
Sean A. Irvine, Table of n, a(n) for n = 1..13
MATHEMATICA
Module[{s18, s81, s29, s92}, s18=Select[Table[FromDigits[PadRight[{}, n, {1, 8}]], {n, 1, 181, 2}], PrimeQ]; s81=Select[Table[FromDigits[PadRight[{}, n, {8, 1}]], {n, 2, 182, 2}], PrimeQ]; s29 = Select[ Table[FromDigits[PadRight[{}, n, {2, 9}]], {n, 2, 182, 2}], PrimeQ]; s92 =Select[Table[ FromDigits[ PadRight[{}, n, {9, 2}]], {n, 1, 183, 2}], PrimeQ]; Join[{2, 3, 5, 7}, s18, s81, s29, s92]//Sort] (* Harvey P. Dale, Mar 23 2023 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Apr 15 1999
STATUS
approved