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%I #5 Aug 07 2012 20:12:19
%S 4,6,9,12,15,18,24,30,36,42,51,60,66,72,87,102,105,108,123,138,144,
%T 150,165,180,186,192,195,198,213,228,234,240,255,270,276,282,297,312,
%U 330,348,384,420,426,432,447,462,492,522,546,570,585,600,609,618,630,642
%N Arithmetic mean of the n-th and (n+1)st twin prime member A001097.
%H T. D. Noe, <a href="/A163656/b163656.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = (A001097(n) + A001097(n+1))/2.
%e a(1) = 4 = (3+5)/2.
%t t = Select[Prime[Range[500]], PrimeQ[# - 2] || PrimeQ[# + 2] &]; (Most[t] + Rest[t])/2 (* _T. D. Noe_, Aug 07 2012 *)
%Y Cf. A014574 (bisection).
%K nonn
%O 1,1
%A _Juri-Stepan Gerasimov_, Aug 02 2009
%E 35 replaced by 36 - _R. J. Mathar_, Aug 06 2009
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