OFFSET
1,1
LINKS
T. D. Noe, Table of n, a(n) for n = 1..10000
Marek Wolf, Search for primes of the form m^2+1, arXiv:0803.1456 [math.NT], 2008-2010.
EXAMPLE
The 5th term is 13 and 4*169+1 = 677 is also a prime.
MATHEMATICA
Select[Prime[Range[300]], PrimeQ[4 #^2 + 1]&] (* Vincenzo Librandi, Apr 11 2013 *)
PROG
(Magma) [p: p in PrimesUpTo(2000) | IsPrime(4*p^2+1)]; // Vincenzo Librandi, Apr 11 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Labos Elemer, Feb 08 2000
STATUS
approved