A062215 Numbers k such that the smoothly undulating palindromic number (19*10^k - 91)/99 is a prime.

3, 33, 133, 1969, 2335

Offset: 1

Author

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

Keywords

• nonn
• base

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=33 -> (19*10^33 - 91)/99 = 191919191919191919191919191919191.
		

Links

• P. De Geest, SUPP Reference Table - 191
• Index entries for sequences related to smoothly undulating palindromic primes

Crossrefs

Cf. A062209-A062232, A059758, A032758.

Extensions

Edited by Ray Chandler, Aug 17 2011