The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A137848 Numbers k such that 10^k + 81 is prime. 1
 2, 6, 8, 17, 22, 39, 89, 143, 167, 312, 334, 357, 414, 2254, 2694, 24094, 42081, 78632 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The next term, if one exists, is >100000. - Robert Price, Apr 25 2011 LINKS Table of n, a(n) for n=1..18. EXAMPLE 10^2+81=100+81=181 is prime MATHEMATICA Select[10^Range[25000] + 81, PrimeQ] (* Alonso del Arte, Dec 27 2010 *) PROG (PARI) is(n)=ispseudoprime(10^n+81) \\ Charles R Greathouse IV, Jun 13 2017 CROSSREFS Sequence in context: A279726 A337881 A331974 * A182629 A331972 A183212 Adjacent sequences: A137845 A137846 A137847 * A137849 A137850 A137851 KEYWORD nonn AUTHOR Vladimir Joseph Stephan Orlovsky, May 06 2008 EXTENSIONS Added three terms: 2254,2694,24094. Robert Price, Oct 09 2010 a(17)=42081 from Robert Price, Dec 27 2010 a(18)=78632 from Robert Price, Mar 03 2011 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 May 21 21:53 EDT 2024. Contains 372738 sequences. (Running on oeis4.)