This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A143828 Primes of the form 10*k^2 - 1. 8
 89, 359, 809, 1439, 4409, 8999, 10889, 12959, 20249, 23039, 35999, 47609, 51839, 56249, 65609, 75689, 98009, 116639, 123209, 129959, 136889, 143999, 151289, 158759, 166409, 234089, 272249, 282239, 302759, 313289, 334889, 404009, 416159 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..5000 MATHEMATICA p = 10; a = {}; Do[k = p x^2 - 1; If[PrimeQ[k], AppendTo[a, k]], {x, 1, 1000}]; a Select[Table[10n^2-1, {n, 1, 800}], PrimeQ] (* Vincenzo Librandi, Dec 07 2011 *) PROG (MAGMA) [a: n in [1..400] | IsPrime(a) where a is 10*n^2-1]; // Vincenzo Librandi, Dec 07 2011 CROSSREFS Cf. A066436, A066049, A090686, A090684, A143826, A143827. Sequence in context: A288024 A118922 A022464 * A253140 A142448 A257118 Adjacent sequences:  A143825 A143826 A143827 * A143829 A143830 A143831 KEYWORD nonn,easy AUTHOR Artur Jasinski, Sep 02 2008 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
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 16 09:06 EST 2019. Contains 330020 sequences. (Running on oeis4.)