A117708 Numbers that are both lucky numbers and Chen primes.

3, 7, 13, 31, 37, 67, 127, 211, 307, 409, 487, 541, 577, 631, 769, 787, 937, 991, 1009, 1039, 1117, 1201, 1291, 1459, 1471, 1567, 1777, 1801, 2251, 2281, 2467, 2557, 2647, 2971, 3037, 3187, 3259, 3307, 3559, 3709, 3847, 3889, 4441, 4567, 4801, 4969, 4987

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Mathematica

lst = Range[1, 5000, 2]; i = 2; While[ i <= (len = Length@lst) && (k = lst[[i]]) <= len, lst = Drop[lst, {k, len, k}]; i++ ]; chenQ[n_] := PrimeQ[n] && Plus @@ Last /@ FactorInteger[n + 2] < 3; Select[lst, chenQ@# &] (* Robert G. Wilson v, May 12 2006 *)

Crossrefs

Intersection of A000959 and A109611.

Subsequence of A031157.

Sequence in context: A136051 A100750 A105435 * A093431 A243765 A256148

Adjacent sequences: A117705 A117706 A117707 * A117709 A117710 A117711

Keyword

nonn

Author

Jani Melik, Apr 27 2006

Extensions

Corrected and extended by Robert G. Wilson v, May 12 2006

Status

approved