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%I #15 Apr 08 2013 03:55:27
%S 113,199,211,223,227,229,233,277,311,331,337,433,443,449,499,557,577,
%T 599,661,677,733,773,811,877,881,883,887,911,977,991,997,1117,1777,
%U 1999,2111,2221,2333,2777,2999,3331,4111,4441,4447,4999,5333,5557,6661,7333,8111,8887,8999
%N Near-repdigit primes such that all digits are equal except for an end-digit.
%H Giovanni Resta, <a href="/A056710/b056710.txt">Table of n, a(n) for n = 1..496</a> (terms < 10^1000)
%t Select[ Range[ 101, 10^4, 2 ], PrimeQ[ # ] && (Length[ Union[ Take[ RealDigits[ # ][ [ 1 ] ], {1, -2} ] ] ] == 1 || Length[ Union[ Take[ RealDigits[ # ][ [ 1 ] ], {2, -1} ] ] ] == 1) & ]
%t dig[n_] := Sort@Select[Flatten@Table[{d*10^(n - 1) + e*(10^(n - 1) - 1)/9, e + 10 d*(10^(n-1)- 1)/9}, {e, {1,3,7,9}}, {d, Delete[Range@9, e]}], PrimeQ]; Join @@ dig /@ Range[3, 100] (* terms < 10^100, _Giovanni Resta_, Apr 08 2013 *)
%K nonn,base
%O 1,1
%A _Robert G. Wilson v_, Aug 10 2000
%E Four missing terms added by _Giovanni Resta_, Apr 07 2013
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