A034784 Numbers n such that A034693(n) = 2.

3, 5, 8, 9, 11, 14, 15, 20, 21, 23, 26, 29, 33, 35, 39, 41, 44, 48, 50, 51, 53, 54, 56, 63, 65, 68, 69, 74, 75, 81, 83, 86, 89, 90, 95, 98, 99, 105, 111, 113, 114, 116, 119, 120, 125, 128, 131, 134, 135, 140, 141, 146, 153, 155, 158, 165, 168, 173, 174, 176

Offset: 1

Author

Labos Elemer

Keywords

• nonn

Links

• Michael De Vlieger, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A034693, A034694.

Programs

Mathematica

CompositeNext[n_]:=Module[{k=n+1},While[PrimeQ[k],k++ ];k]; lst={};Do[p=n+CompositeNext[n];If[PrimeQ[p],AppendTo[lst,n]],{n,2,6!}];lst (* Vladimir Joseph Stephan Orlovsky, Jun 15 2009 *)
Position[#, 2] &@ Table[k = 1; While[! PrimeQ[k n + 1], k++]; k, {n, 180}] // Flatten (* Michael De Vlieger, Mar 02 2017 *)

Extensions

Edited by N. J. A. Sloane, Oct 27 2012