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Values of k such that 10*k+1 and 10*k+9 alone are prime between 10*k and 10*k+9.
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%I #11 Sep 07 2012 01:04:23

%S 40,49,70,76,91,157,253,274,301,304,322,349,370,388,475,505,517,622,

%T 652,715,769,817,868,931,994,1015,1039,1063,1078,1132,1168,1228,1240,

%U 1279,1315,1324,1378,1441,1477,1555,1567,1687,1723,1735,1819,1837,1867,1900

%N Values of k such that 10*k+1 and 10*k+9 alone are prime between 10*k and 10*k+9.

%H V. Raman, <a href="/A216305/b216305.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) >> n log^2 n. - _Charles R Greathouse IV_, Sep 07 2012

%t t = {}; Do[ps = Select[Range[10*n, 10*n + 9], PrimeQ]; If[ps == {10*n + 1, 10*n + 9}, AppendTo[t, n]], {n, 0, 3319}]; t (* _T. D. Noe_, Sep 04 2012 *)

%Y Cf. A032352, A007811, A078494.

%K nonn

%O 1,1

%A _V. Raman_, Sep 03 2012