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 A082712 Numbers k such that (67*10^(k-1) + 23)/9 is a depression prime. 1
 11, 31, 121, 485, 1487, 1579, 13673, 13811, 15095, 72773, 94212 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Prime versus probable prime status and proofs are given in the author's table. 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 - 747. Makoto Kamada, Prime numbers of the form 744...447. FORMULA a(n) = A056258(n) + 2. EXAMPLE k=11 -> (67*10^(11-1) + 23)/9 = 74444444447. CROSSREFS Cf. A082697-A082720, A056258. Sequence in context: A223388 A152220 A272263 * A049090 A181150 A094622 Adjacent sequences:  A082709 A082710 A082711 * A082713 A082714 A082715 KEYWORD nonn,base,hard,more AUTHOR Patrick De Geest, Apr 13 2003 EXTENSIONS a(10)=72773 from Ray Chandler, Nov 16 2010 a(11)=94212 from Ray Chandler, Feb 21 2011 Edited by Ray Chandler, Nov 05 2014 STATUS approved

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Last modified April 8 05:55 EDT 2020. Contains 333312 sequences. (Running on oeis4.)