This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A183184 Numbers n such that 10^(2n+1)-8*10^n-1 is prime. 1
 1, 5, 13, 43, 169, 181, 1579, 18077, 22652, 157363 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 REFERENCES C. Caldwell and H. Dubner, "Journal of Recreational Mathematics", Volume 28, No. 1, 1996-97, pp. 1-9. LINKS Patrick De Geest, World!Of Numbers, Palindromic Wing Primes (PWP's) Makoto Kamada, Prime numbers of the form 99...99199...99 FORMULA a(n) = (A077776(n)-1)/2. MATHEMATICA Do[If[PrimeQ[10^(2n + 1) - 8*10^n - 1], Print[n]], {n, 3000}] PROG (PARI) is(n)=ispseudoprime(10^(2*n+1)-8*10^n-1) \\ Charles R Greathouse IV, Jun 13 2017 CROSSREFS Cf. A004023, A077775-A077798, A107123-A107127, A107648, A107649, A115073, A183174-A183187. Sequence in context: A093576 A147259 A183315 * A115785 A218926 A113835 Adjacent sequences:  A183181 A183182 A183183 * A183185 A183186 A183187 KEYWORD nonn,base AUTHOR Ray Chandler, Dec 28 2010 EXTENSIONS Added one more term from PWP table, by Patrick De Geest, Nov 05 2014 STATUS approved

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

Last modified September 23 20:33 EDT 2017. Contains 292391 sequences.