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a(n) is the largest prime before A002282(n) repdigits.
10

%I #9 Jul 26 2022 21:59:07

%S 7,83,887,8887,88883,888887,8888861,88888883,888888887,8888888837,

%T 88888888859,888888888887,8888888888857,88888888888873,

%U 888888888888883,8888888888888753,88888888888888801,888888888888888859

%N a(n) is the largest prime before A002282(n) repdigits.

%e n=2: 83 is before 88.

%t <<NumberTheory`NumberTheoryFunctions` Table[Table[PreviousPrime[8*(10^n-1)/9], {n, 1, 35}]

%t Table[NextPrime[FromDigits[PadRight[{},n,8]],-1],{n,20}] (* _Harvey P. Dale_, Jul 12 2014 *)

%Y Cf. A003618, A003617, A096497, A096498, A068104, A002275-A002283, A099656-A099667.

%K base,nonn

%O 1,1

%A _Labos Elemer_, Nov 17 2004