A220142 The values of k in A220141.
2, 6, 18, 24, 42, 54, 120, 258, 396, 480, 612, 840, 1074, 1800, 2130, 2172, 2256, 2550, 2694, 3282, 3492, 3690, 3810, 4110, 4626, 4788, 4860, 4992, 5148, 5280, 5958, 5994, 6804, 7920, 9654, 9660, 11082, 16134
Offset: 1
Programs
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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][[2]]
Extensions
More terms from Amiram Eldar, Dec 30 2019