A138906 a(n) is n-th prime == 1 (mod 6n).

7, 37, 73, 241, 211, 433, 463, 769, 811, 1321, 1321, 2089, 1951, 2689, 2791, 4513, 3469, 5077, 6271, 6121, 6427, 7129, 7177, 10369, 7951, 10453, 10531, 13441, 15139, 12601, 18229, 15937, 17623, 21013, 15331, 24841, 23977, 26449, 24571, 24481

Offset: 1

Author

Zak Seidov, Apr 03 2008

Keywords

• nonn

Crossrefs

Cf. A138905, A138907.

Programs

Mathematica

a[n_]:=Module[{p=1,cnt=0},Until[cnt==n,If[Mod[Prime[p],6n]==1,cnt++];p++];Prime[p-1]];Array[a,40] (* James C. McMahon, Jun 23 2025 *)