A105585 1, p and 3p, where p runs through all primes except 2 and 5.

1, 3, 7, 9, 11, 13, 17, 19, 21, 23, 29, 31, 33, 37, 39, 41, 43, 47, 51, 53, 57, 59, 61, 67, 69, 71, 73, 79, 83, 87, 89, 93, 97, 101, 103, 107, 109, 111, 113, 123, 127, 129, 131, 137, 139, 141, 149, 151, 157, 159, 163, 167, 173, 177, 179, 181, 183, 191, 193, 197, 199, 201, 211

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Maple

v1:=[1, 3, seq(ithprime(i), i=4..100)]; v2:=3*v1; v3:=[op(v1), op(v2)]; v4:=convert(v3, set); convert(%, list); sort(%);

Mathematica

Module[{nn=50}, Select[Sort[Flatten[Join[{1, 3, 9}, Table[{n, 3n}, {n, Prime[ Range[ 4, nn]]}]]]], #<=Prime[nn]&]] (* Harvey P. Dale, Jun 16 2019 *)

Crossrefs

Sequence in context: A085820 A045572 A069254 * A080903 A172253 A104381

Adjacent sequences: A105582 A105583 A105584 * A105586 A105587 A105588

Keyword

nonn

Author

N. J. A. Sloane, Sep 03 2008

Status

approved