OFFSET
1,1
COMMENTS
It is easy to show that k mod 12 must be 2,4,8,10 and that since k^2 mod 12 = 4, then p mod 12 = 1. In base 12, the sequence is 11, 61, 91, 2X1, 721, X11, E21, 16X1, 1E51, 2291, 2X11, 3X91, 45X1, 5691, 5961, 7011, 7321, 8091, E421, E811, 129X1, where X is for 10, E is for 11. - Walter Kehowski, May 31 2008
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
MATHEMATICA
Intersection[Table[n^2+9, {n, 0, 10^2}], Prime[Range[9*10^3]]] ...or... For[i=9, i<=9, a={}; Do[If[PrimeQ[n^2+i], AppendTo[a, n^2+i]], {n, 0, 100}]; Print["n^2+", i, ", ", a]; i++ ]
Select[Range[400]^2+9, PrimeQ] (* Harvey P. Dale, Jan 31 2017 *)
PROG
(Magma) [ a: n in [0..900] | IsPrime(a) where a is n^2+9] // Vincenzo Librandi, Nov 24 2010
(Haskell)
a138353 n = a138353_list
a138353_list = filter ((== 1) . a010051') $ map (+ 9) a000290_list
-- Reinhard Zumkeller, Mar 12 2012
(PARI) is(n)=isprime(n) && issquare(n-9) \\ Charles R Greathouse IV, Aug 21 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Joseph Stephan Orlovsky, May 07 2008
EXTENSIONS
More terms from Vincenzo Librandi, Apr 28 2010
STATUS
approved