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A036949 Smallest n-digit prime containing only the digits 7 and 8, or 0 if no such prime exists. 1
7, 0, 787, 7877, 78787, 777787, 7778777, 77778887, 777788887, 7777778887, 77777778887, 777777777877, 7777777787777, 77777777778787, 777777777777787, 7777777778788777, 77777777777778887, 777777777787878887 (list; graph; refs; listen; history; text; internal format)
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 A271697

Adjacent sequences:  A036946 A036947 A036948 * A036950 A036951 A036952

KEYWORD

nonn,base

AUTHOR

Patrick De Geest, Jan 04 1999

STATUS

approved

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Last modified May 26 17:16 EDT 2022. Contains 354092 sequences. (Running on oeis4.)