The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 60th year, we have over 367,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A082710 Numbers k such that (64*10^(k-1) + 53)/9 is a depression prime. 0
 10907, 499211 (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. Searched up to k=1200000 by Serge Batalov, Mar 02 2015 REFERENCES C. Caldwell and H. Dubner, "Journal of Recreational Mathematics", Volume 28, No. 1, 1996-97, pp. 1-9. LINKS Table of n, a(n) for n=1..2. Patrick De Geest, PDP Reference Table - 717. Makoto Kamada, Prime numbers of the form 711...117. Tanya Khovanova, Non Recursions C. Rivera and J.C. Rosa, Puzzle 197. Always composite numbers? EXAMPLE a(1)=10907 -> (64*10^(10907-1) + 53)/9 = 7111...1117 or 10905 1's surrounded by two 7's. CROSSREFS Cf. A082697-A082720. Sequence in context: A084277 A307873 A259138 * A240604 A065322 A166261 Adjacent sequences: A082707 A082708 A082709 * A082711 A082712 A082713 KEYWORD nonn,bref,base,hard,more AUTHOR Patrick De Geest, Apr 13 2003 EXTENSIONS Edited by Ray Chandler, Nov 05 2014 Additional PRP term 499211 by Serge Batalov, Mar 01 2015 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 6 16:13 EST 2023. Contains 367612 sequences. (Running on oeis4.)