A134926 Nearest-neighbors of odd isolated primes, divided by 2.

11, 12, 18, 19, 23, 24, 26, 27, 33, 34, 39, 40, 41, 42, 44, 45, 48, 49, 56, 57, 63, 64, 65, 66, 78, 79, 81, 82, 83, 84, 86, 87, 105, 106, 111, 112, 116, 117, 125, 126, 128, 129, 131, 132, 138, 139, 146, 147, 153, 154, 158, 159, 165, 166

Offset

1,1

Links

Table of n, a(n) for n=1..54.

Mathematica

ip=Select[Prime[Range[2, 67]], NoneTrue[{#-2, #+2}, PrimeQ]&]; Union[Flatten[Table[n+{1, -1}, {n, ip}]/2]] (* James C. McMahon, Apr 12 2025 *)

Crossrefs

Cf. A134924.

Sequence in context: A087450 A176650 A046465 * A105744 A092096 A057303

Adjacent sequences: A134923 A134924 A134925 * A134927 A134928 A134929

Keyword

easy,nonn

Author

Omar E. Pol, Nov 27 2007

Status

approved