A082711 Numbers k such that (65*10^(k-1) + 43)/9 is a depression prime.
3, 5, 9, 29, 65, 725, 1787, 7277, 19463, 24215, 51779, 131393
Offset: 1
Examples
k=9 -> (65*10^(9-1) + 43)/9 = 722222227.
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 - 727.
- Makoto Kamada, Prime numbers of the form 722...227.
- Index entries for primes involving repunits.
Formula
a(n) = A056257(n) + 2.
Extensions
Update from De Geest site by Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008
a(11)=51779 from Ray Chandler, Nov 16 2010
Edited by Ray Chandler, Nov 05 2014
a(12) from Tyler Busby, Feb 01 2023
Comments