The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A181732 Numbers n such that 90n + 1 is prime. 26
 2, 3, 6, 7, 9, 11, 13, 17, 18, 20, 24, 25, 26, 28, 31, 33, 34, 37, 39, 41, 45, 47, 51, 54, 55, 62, 65, 68, 69, 70, 72, 73, 74, 76, 84, 86, 89, 90, 91, 94, 96, 97, 98, 100, 101, 102, 107, 108, 109, 110, 117, 119, 121, 123, 124, 125, 130, 133, 136, 138, 139, 140 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Alois P. Heinz, Table of n, a(n) for n = 1..10000 FORMULA a(n) = (1/90) [A142312(n) - 1]. a(n) ~ (4/15) n log n. - Charles R Greathouse IV, Jun 01 2016, corrected Sep 05 2016 MAPLE a:= proc(n) option remember; local k;        for k from 1+ `if`(n=1, 1, a(n-1))        while not isprime(90*k+1) do od; k     end: seq(a(n), n=1..100);  # Alois P. Heinz, Dec 05 2011 MATHEMATICA Select[Range[200], PrimeQ[90 # + 1] &] (* Vincenzo Librandi, Sep 06 2016 *) PROG (PARI) is(n)=n%90==1 && isprime(n) \\ Charles R Greathouse IV, Jun 01 2016 (MAGMA) [n: n in [0..200]| IsPrime(90*n+1)]; // Vincenzo Librandi, Sep 06 2016 CROSSREFS Cf. A142312. Complement of A255491. Sequence in context: A259726 A259587 A304107 * A190199 A014873 A029467 Adjacent sequences:  A181729 A181730 A181731 * A181733 A181734 A181735 KEYWORD nonn,easy AUTHOR J. W. Helkenberg, Nov 16 2010 EXTENSIONS New name from Michael B. Porter, Jul 26 2013 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 August 15 00:24 EDT 2020. Contains 336484 sequences. (Running on oeis4.)