login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

A155771
Numbers n such that 2*n^2+2*n-41 is a prime.
4
5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 25, 27, 28, 29, 33, 34, 39, 42, 44, 45, 46, 48, 50, 52, 53, 56, 57, 58, 59, 61, 65, 66, 68, 69, 74, 77, 80, 83, 86, 87, 90, 91, 93, 95, 96, 99, 101, 103, 104, 106, 107, 110, 116, 121, 126, 128, 130, 131, 133, 136
OFFSET
1,1
LINKS
EXAMPLE
For n=14, a(14)=379; n=140, a(140)=39439.
MATHEMATICA
Select[Range[4, 200], PrimeQ[2#^2+2#-41]&] (* Vincenzo Librandi, Sep 24 2012 *)
PROG
(Magma) [n: n in [4..150] | IsPrime(2*n^2+2*n-41)]; // Vincenzo Librandi, Sep 24 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Jan 27 2009
STATUS
approved