A062225 Numbers k such that the smoothly undulating palindromic number (78*10^k - 87)/99 is a prime.

3, 5, 21, 27, 95, 2075, 2165, 3047, 3503, 16791, 34883

Offset: 1

Author

Patrick De Geest and Hans Rosenthal (Hans.Rosenthal(AT)t-online.de), Jun 15 2001

Keywords

• nonn
• base
• more

Comments

Prime versus probable prime status and proofs are given in the author's table.

No further terms < 100000. - Ray Chandler, Aug 17 2011

Examples

			k=21 -> (78*10^21 - 87)/99 = 787878787878787878787.
		

Links

• Patrick De Geest, SUPP Reference Table - 787
• Index entries for sequences related to smoothly undulating palindromic primes

Crossrefs

Cf. A062209-A062232, A059758, A032758.

Extensions

Edited by Ray Chandler, Aug 17 2011