A036949 Smallest n-digit prime containing only the digits 7 and 8, or 0 if no such prime exists.

7, 0, 787, 7877, 78787, 777787, 7778777, 77778887, 777788887, 7777778887, 77777778887, 777777777877, 7777777787777, 77777777778787, 777777777777787, 7777777778788777, 77777777777778887, 777777777787878887

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

Cf. A020470, A036229, A036323.

Sequence in context: A240810 A024094 A157307 * A059515 A136428 A378843

Adjacent sequences: A036946 A036947 A036948 * A036950 A036951 A036952

Keyword

nonn,base

Author

Patrick De Geest, Jan 04 1999

Status

approved