A067529 n - 5^k is a prime for all k > 0 and n > 5^k.

7, 8, 10, 12, 16, 18, 22, 24, 28, 36, 42, 48, 66, 72, 78, 84, 108, 114, 132, 156, 162, 198, 204, 276, 282, 288, 318, 336, 492, 504, 546, 582, 612, 624, 666, 864, 882, 1044, 1134, 1218, 1242, 1326, 1452, 1998, 2136, 2472, 2922, 3234, 3948, 4032, 4572, 4914, 6342

Offset

1,1

Comments

Is the sequence finite?

The last term appears to be 7726572. - T. D. Noe, Nov 23 2004

Links

Michel Marcus, Table of n, a(n) for n = 1..66

Walter E. Mientka and Roger C. Weitzenkamp, On f-plentiful numbers, Journal of Combinatorial Theory, Volume 7, Issue 4, December 1969, Pages 374-377

Example

624 is a term as 624-5, 624-25,624-125 or 619,599 and 499 are primes.

Mathematica

lst={}; Do[k=1; While[p=n-5^k; p>0 && PrimeQ[p], k++ ]; If[p<=0, AppendTo[lst, n]], {n, 6, 10^7}]; lst (T. D. Noe)

Crossrefs

Cf. A067526, A067527, A067528.

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

Sequence in context: A120175 A291668 A175222 * A080113 A243078 A048588

Adjacent sequences: A067526 A067527 A067528 * A067530 A067531 A067532

Keyword

easy,nonn

Author

Amarnath Murthy, Feb 17 2002

Extensions

More terms from Sascha Kurz, Mar 19 2002

Status

approved