A210939 - OEIS

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

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OFFSET

1,2

COMMENTS

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

LINKS

Table of n, a(n) for n=1..59.

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 *)

CROSSREFS

Nonprimes in A045718.

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

Sequence in context: A360127 A111305 A284665 * A175246 A353537 A134928

Adjacent sequences: A210936 A210937 A210938 * A210940 A210941 A210942

KEYWORD

nonn

AUTHOR

Omar E. Pol, Apr 17 2012

STATUS

approved