A082698 Numbers k such that (13*10^(k-1) - 31)/9 is a plateau prime.

7, 67, 1255, 8407, 67039

Offset: 1

Author

Patrick De Geest, Apr 13 2003

Keywords

• nonn
• base
• more

Comments

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

a(6) > 2*10^5. - Tyler Busby, Feb 02 2023

Examples

			k=7 -> (13*10^(7-1) - 31)/9 = 1444441.
		

References

• C. Caldwell and H. Dubner, "Journal of Recreational Mathematics", Volume 28, No. 1, 1996-97, pp. 1-9.

Links

• Patrick De Geest, PDP Reference Table - 141.
• Makoto Kamada, Prime numbers of the form 144...441.
• Index entries for primes involving repunits.

Crossrefs

Cf. A056245, A082697-A082720.

Formula

a(n) = A056245(n+1) + 2.

Extensions

A new PRP term from Serge Batalov, Nov 02 2008

Edited by Ray Chandler, Nov 04 2014