OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
a(1)=3 as 12+-5 are primes. a(2)=6 as 42+-5 are primes.
MAPLE
select(n -> isprime(n^2+n+5) and isprime(n^2+n-5), [$1..2000]); # Robert Israel, Nov 26 2017
MATHEMATICA
q=5; lst5={}; Do[p=n^2+n; If[PrimeQ[p-q]&&PrimeQ[p+q], AppendTo[lst5, n]], {n, 0, 7!}]; lst5
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vladimir Joseph Stephan Orlovsky, Jun 20 2009
EXTENSIONS
Definition rephrased by R. J. Mathar, Jun 23 2009
STATUS
approved