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%I
%S 3,5,7,13,19,31,43,61,79,103,127,139,151,157,163,181,199,211,223,277,
%T 331,349,367,373,379,409,439,463,487,547,607,613,619,631,643,691,739,
%U 811,883,937,991,1021,1051,1069,1087,1129,1171,1201,1231,1279,1327,1399
%N Beginning with 3, primes such that a(2n) = {a(2n-1) +a(2n+1)}/2.
%C For n > 1, a(2n) = smallest prime of the form a(2n-1) + 6k where a(2n-1) + 12k is also a prime and is equal to a(2n+1). The difference of successive terms is 2,2,6,6,12,12,18,18,24,24,12,12,6,6,18,18,...
%H Vincenzo Librandi, <a href="/A084696/b084696.txt">Table of n, a(n) for n = 1..1000</a>
%t f[l_List] := Block[{p = Last[l], k = 2, t},While[t = {p + k, p + 2k}; ! And @@ PrimeQ /@ t, k += 2 ];Join[l, t]];Nest[f, {3}, 26] (*Chandler*)
%Y A122809 gives bisection of first difference/2 of this sequence.
%K nonn
%O 1,1
%A Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Jun 05 2003
%E More terms from _David Wasserman_, Dec 30 2004
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