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%I #6 Oct 09 2018 19:49:35
%S 283,28888883,88888888888889,88888888888888889,
%T 28888888888888888888888888883,6888888888888888888888888888888887,
%U 88888888888888888888888888888888889,6888888888888888888888888888888888888888888888888888888888888888888888887,28888888888888888888888888888888888888888888888888888888888888888888888883
%N Primes such that the outer 2 digits are n and n+1 and all inner digits are 8, where 0 < n < 9.
%F a(x) = 10^(x+1)*n+floor(10^x*8/9)*10+n+1. Output if a(x) is prime.
%t Select[FromDigits/@Flatten[Table[Join[{n},PadRight[{},k,8],{n+1}],{n,8},{k,100}],1],PrimeQ]//Sort (* _Harvey P. Dale_, Oct 09 2018 *)
%o (PARI) n10np1(n) = { local(x,y,k); for(x=1,n, for(k=1,8, y=10^(x+1)*k+floor(10^x*8/9)*10+k+1; if(isprime(y),print1(y",")) ) ) }
%K easy,nonn,base
%O 1,1
%A _Cino Hilliard_, Jul 11 2005
%E More terms from _Harvey P. Dale_, Oct 09 2018
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