A134926 -id:A134926 - cp's OEIS frontend

A134924 Nearest-neighbors of isolated primes.

1, 3, 22, 24, 36, 38, 46, 48, 52, 54, 66, 68, 78, 80, 82, 84, 88, 90, 96, 98, 112, 114, 126, 128, 130, 132, 156, 158, 162, 164, 166, 168, 172, 174, 210, 212, 222, 224, 232, 234, 250, 252, 256, 258, 262, 264, 276, 278, 292, 294, 306, 308

Offset: 1

Omar E. Pol, Nov 27 2007

Martin Burtscher, Igor Szczyrba, and Rafał Szczyrba, Analytic Representations of the n-anacci Constants and Generalizations Thereof, Journal of Integer Sequences, Vol. 18 (2015), Article 15.4.5.

Cf. A007510, A045718, A134926, A134930.

ip=Select[Prime[Range[65]],NoneTrue[{#-2,#+2},PrimeQ]&];Union[Flatten[Table[n+{1, -1}, {n, ip}]]] (* James C. McMahon, Apr 12 2025 *)

A147820 Nearest-neighbors of odd primes, divided by 2.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 18, 19, 20, 21, 22, 23, 24, 26, 27, 29, 30, 31, 33, 34, 35, 36, 37, 39, 40, 41, 42, 44, 45, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 63, 64, 65, 66, 68, 69, 70, 74, 75, 76, 78, 79, 81

Offset: 1

Omar E. Pol, Nov 14 2008

Cf. A134926, A134933, A147819.

Union[Flatten[{(#-1)/2,(#+1)/2}&/@Prime[Range[2,40]]]] (* Harvey P. Dale, Oct 19 2011 *)

a(n) = A147819(n)/2.

cp's OEIS Frontend

A134924 Nearest-neighbors of isolated primes.

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