A210939 Nonprime nearest-neighbors of the primes.

1, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 30, 32, 36, 38, 40, 42, 44, 46, 48, 52, 54, 58, 60, 62, 66, 68, 70, 72, 74, 78, 80, 82, 84, 88, 90, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 126, 128, 130, 132, 136, 138, 140, 148, 150, 152, 156

Offset: 1

Author

Omar E. Pol, Apr 17 2012

Keywords

• nonn

Comments

Essentially the same as A147819. R. J. Mathar, Jun 25 2012

Crossrefs

Nonprimes in A045718.

Cf. A000040, A018252, A134928, A134930, A210940.

Programs

Mathematica

Select[Range[156], ! PrimeQ[#] && (PrimeQ[# - 1] || PrimeQ[# + 1]) &] (* T. D. Noe, Apr 18 2012 *)
Join[{1},Flatten[#+{-1,1}&/@Prime[Range[3,40]]]//Union] (* Harvey P. Dale, Oct 22 2022 *)