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Numbers n such that the two numbers n+1 and n+3 are both prime.
4

%I #21 Apr 17 2018 11:44:16

%S 2,4,10,16,28,40,58,70,100,106,136,148,178,190,196,226,238,268,280,

%T 310,346,418,430,460,520,568,598,616,640,658,808,820,826,856,880,1018,

%U 1030,1048,1060,1090,1150,1228,1276,1288,1300,1318,1426,1450,1480,1486,1606

%N Numbers n such that the two numbers n+1 and n+3 are both prime.

%C 1 less than the lesser of each twin prime pair. [_Harvey P. Dale_, Nov 08 2011]

%H Harvey P. Dale, <a href="/A144834/b144834.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = A014574(n)-2 = A001359(n)-1. - _R. J. Mathar_, Sep 24 2008

%t Transpose[Select[Partition[Prime[Range[300]],2,1],Last[#]-First[#] == 2&]][[1]]-1 (* _Harvey P. Dale_, Nov 08 2011 *)

%Y Cf. A053319 (first differences).

%K easy,nonn

%O 1,1

%A _Giovanni Teofilatto_, Sep 22 2008

%E Definition edited and extended by _R. J. Mathar_, Sep 24 2008