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%I #19 Mar 01 2022 07:25:35
%S 0,1,8,9,10,14,15,16,20,21,22,24,25,26,27,28,32,33,34,35,36,38,39,40,
%T 44,45,46,48,49,50,51,52,54,55,56,57,58,62,63,64,65,66,68,69,70,74,75,
%U 76,77,78,80,81,82,84,85,86,87,88,90,91,92,93,94,95,96,98,99,100,104,105,106,110
%N The non-isolated nonprimes.
%C Non-isolated nonprimes in the sense that at least one of the two adjacent integers is also a nonprime.
%H G. C. Greubel, <a href="/A164276/b164276.txt">Table of n, a(n) for n = 1..1000</a>
%F A141468 \ A014574.
%F a(n) = n + n / log n + O(n / (log n)^2) by Brun's theorem. - _Charles R Greathouse IV_, Mar 15 2011
%t Select[Range[0,100], !PrimeQ[#] && (!PrimeQ[# - 1] || !PrimeQ[# + 1]) & ] (* _G. C. Greubel_, Jul 07 2016 *)
%o (PARI) isA164276(n) = !isprime(n)&&(!isprime(n-1)||!isprime(n+1)) \\ _Michael B. Porter_, Feb 02 2010
%Y Cf. A014574, A141468.
%K nonn,easy
%O 1,3
%A _Juri-Stepan Gerasimov_, Aug 11 2009
%E 40 added by _R. J. Mathar_, Aug 27 2009
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