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Smallest prime of the form: all sevens followed by prime(n); a(n) > prime(n); or 0 if no such prime exists.
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%I #6 Mar 24 2021 05:58:43

%S 0,73,0,0,77711,77713,7717,719,7723,77777777777777777729,77731,777737,

%T 7741,743,77747,7753,7759,761,77777777767,7777777777771,773,

%U 777777777777777777777777777777777777777777777777777777777777777779

%N Smallest prime of the form: all sevens followed by prime(n); a(n) > prime(n); or 0 if no such prime exists.

%C Prime(n) is all zeros followed by prime(n).This is all sevens followed by prime(n). Conjecture: a(n) is nonzero if n >4.

%C The conjecture has been verified for n<100. - Joshua Albert (jba138(AT)psu.edu), Jan 20 2006

%e a(9) = 7723, as 723 is composite, prime(9) = 23.

%t Join[{0,73,0,0},Flatten[Select[#,PrimeQ,1]&/@Table[FromDigits[ PadLeft[ IntegerDigits[n],i,7]],{n,Prime[Range[5,30]]},{i,IntegerLength[ n]+1, 100}]]] (* _Harvey P. Dale_, Nov 20 2013 *)

%Y Cf. A113884, A114785, A113886, A113887, A085074.

%K base,nonn

%O 1,2

%A _Amarnath Murthy_, Nov 18 2005

%E More terms from Joshua Albert (jba138(AT)psu.edu), Jan 20 2006