A161346 a(n) = A161345(n)/3.

3, 4, 5, 6, 7, 9, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271

Offset: 1

Author

Omar E. Pol, Jun 20 2009

Keywords

• easy
• nonn

Comments

Union of {4, 6, 9} and all the odd primes. - Amiram Eldar, Apr 17 2024

Links

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

Crossrefs

Cf. A018253, A160811, A160812, A161205, A161344, A161345.

Programs

Mathematica

Select[Range[271], Function[{n, s}, Max[TakeWhile[Divisors[n], # <= s &]] == 3] @@ {#, Sqrt@ #} &[3 #] &] (* Michael De Vlieger, Feb 14 2020 *)

Extensions

Terms beyond a(10) from R. J. Mathar, Jun 24 2009