A220141 Prime numbers p that yield a new record for the least number k such that p*k + 1 and p*k - 1 are twin primes.

2, 5, 11, 13, 31, 37, 53, 61, 433, 3023, 3989, 4079, 9967, 10789, 76943, 81439, 121763, 233969, 491333, 495931, 795659, 1653901, 2623969, 3516277, 6274823, 10536689, 11313839, 12023191, 16268899, 22829309, 38968109, 41230733, 45057577, 76384717, 98566373, 552843883

Offset: 1

Author

T. D. Noe, Jan 08 2013

Keywords

• nonn

Comments

These are the primes at which A071407 reaches a new record. The corresponding values of k are in A220142.

Links

• Amiram Eldar, Table of n, a(n) for n = 1..38

Crossrefs

Cf. A071407, A220142.

Programs

Mathematica

t = {{2, 2}}; Do[k = 1; While[! (PrimeQ[k*n - 1] && PrimeQ[k*n + 1]), k++]; If[k > t[[-1, 2]], AppendTo[t, {n, k}]], {n, Prime[Range[2, 1000]]}]; Transpose[t][[1]]

Extensions

More terms from Amiram Eldar, Dec 30 2019