A062220 Numbers k such that the smoothly undulating palindromic number (38*10^k - 83)/99 is a prime.

3, 9, 15, 17, 21, 57, 4233, 4335, 13221, 26447, 29897, 91997

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=21 -> (38*10^21 - 83)/99 = 383838383838383838383.
		

Links

• P. De Geest, SUPP Reference Table - 383
• Index entries for sequences related to smoothly undulating palindromic primes

Crossrefs

Cf. A062209-A062232, A059758, A032758.

Extensions

a(12)=91997 from Ray Chandler, Jul 29 2011

Edited by Ray Chandler, Aug 17 2011