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A082711
Numbers k such that (65*10^(k-1) + 43)/9 is a depression prime.
1
3, 5, 9, 29, 65, 725, 1787, 7277, 19463, 24215, 51779, 131393
OFFSET
1,1
COMMENTS
Prime versus probable prime status and proofs are given in the author's table.
a(13) > 2*10^5. - Tyler Busby, Feb 01 2023
REFERENCES
C. Caldwell and H. Dubner, "Journal of Recreational Mathematics", Volume 28, No. 1, 1996-97, pp. 1-9.
FORMULA
a(n) = A056257(n) + 2.
EXAMPLE
k=9 -> (65*10^(9-1) + 43)/9 = 722222227.
CROSSREFS
KEYWORD
nonn,base,hard,more
AUTHOR
Patrick De Geest, Apr 13 2003
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
STATUS
approved