A067527 n - 3^k is a prime for all k > 0 such that 3^k < n.

5, 6, 8, 14, 16, 20, 22, 26, 32, 40, 46, 50, 56, 70, 110, 140, 260, 470, 1190, 1330

Offset: 1

Author

Amarnath Murthy, Feb 17 2002

Keywords

• nonn
• hard
• more

Comments

Is the sequence finite?

No other terms below 3^36. - Max Alekseyev, Dec 12 2011

Examples

			40 is a member as 40 - 3 = 37, 40 - 9 = 31, 40 - 27 = 13 are all primes.
		

Crossrefs

Cf. A067526.

Cf. A039669 (n - 2^k is prime).

Programs

Mathematica

A067527 = {}; Do[k = 1; While[p = n - 3^k; p > 0 && PrimeQ[p], k++]; If[p <= 0, AppendTo[A067527, n]], {n, 4, 10000}]; A067527 (* T. D. Noe, Feb 20 2005 *)

Extensions

More terms from Sascha Kurz, Mar 18 2002

Edited by Max Alekseyev, Dec 12 2011