A082701 Numbers k such that (16*10^(k-1) - 61)/9 is a plateau prime.

7, 49, 103, 193, 367, 1003, 20365, 37447, 56083

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.

Examples

			k=7 -> (16*10^(7-1) - 61)/9 = 1777771.
		

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 - 171.
• Makoto Kamada, Prime numbers of the form 177...771.
• Index entries for primes involving repunits.

Crossrefs

Cf. A082697-A082720, A056248.

Formula

a(n) = A056248(n+1) + 2.

Extensions

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008

Edited by Ray Chandler, Nov 04 2014