This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A210939 #19 Oct 22 2022 14:02:28
%S A210939 1,4,6,8,10,12,14,16,18,20,22,24,28,30,32,36,38,40,42,44,46,48,52,54,
%T A210939 58,60,62,66,68,70,72,74,78,80,82,84,88,90,96,98,100,102,104,106,108,
%U A210939 110,112,114,126,128,130,132,136,138,140,148,150,152,156
%N A210939 Nonprime nearest-neighbors of the primes.
%C A210939 Essentially the same as A147819. _R. J. Mathar_, Jun 25 2012
%t A210939 Select[Range[156], ! PrimeQ[#] && (PrimeQ[# - 1] || PrimeQ[# + 1]) &] (* _T. D. Noe_, Apr 18 2012 *)
%t A210939 Join[{1},Flatten[#+{-1,1}&/@Prime[Range[3,40]]]//Union] (* _Harvey P. Dale_, Oct 22 2022 *)
%Y A210939 Nonprimes in A045718.
%Y A210939 Cf. A000040, A018252, A134928, A134930, A210940.
%K A210939 nonn
%O A210939 1,2
%A A210939 _Omar E. Pol_, Apr 17 2012