A138905 a(n) is n-th prime == -1 (mod 6n).

5, 23, 71, 167, 179, 431, 461, 863, 863, 839, 1583, 1511, 1949, 2099, 2339, 4127, 4283, 4751, 4673, 4919, 5669, 6599, 8693, 10079, 7349, 10607, 12149, 11087, 12527, 11159, 15809, 19583, 16829, 19583, 13859, 25703, 24197, 25307, 23633, 21839, 34439

Offset

1,1

Links

David Radcliffe, Table of n, a(n) for n = 1..10000

Example

a(1) = 1st term in A007528 (Primes of form 6n-1)
a(2) = 2nd term in A068231 (Primes congruent to 11 (mod 12))
a(3) = 3rd term in A061242 (Primes of form 18n-1)
a(4) = 4th term in A134517 (Primes of form 24n-1)
a(5) = 5th term in A132236 (Primes congruent to 29 (mod 30))

Mathematica

a[n_]:=Module[{p=1, cnt=0}, Until[cnt==n, If[Mod[Prime[p], 6n]==6n-1, cnt++]; p++]; Prime[p-1]]; Array[a, 41] (* James C. McMahon, Jun 22 2025 *)

Crossrefs

Cf. A007528, A061242, A068231, A093871, A132236, A134517, A138906, A138907.

Sequence in context: A243442 A064395 A230497 * A125955 A103478 A327976

Adjacent sequences: A138902 A138903 A138904 * A138906 A138907 A138908

Keyword

nonn

Author

Zak Seidov, Apr 03 2008

Status

approved