OFFSET
1,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
EXAMPLE
The associated primes are p=5 for n=1, p=19 for n=2, p=43 for n=3, p=239 for n=7.
MAPLE
for n from 1 to 3000 do p := 5*n^2-n+1 ; if isprime(p) then printf("%d, ", n) ; fi; od: # R. J. Mathar, Jan 12 2009
MATHEMATICA
Select[Range[0, 300], PrimeQ[5*#^2 -# +1]&] (* Vincenzo Librandi, Sep 24 2012 *)
PROG
(Magma) [n: n in [0..300] | IsPrime(5*n^2 - n + 1)]; // Vincenzo Librandi, Sep 24 2012
(PARI) is(n)=isprime(5*n^2-n+1) \\ Charles R Greathouse IV, Sep 24 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Jan 09 2009
EXTENSIONS
114 removed; extended by R. J. Mathar, Jan 12 2009
Misleading formula removed by R. J. Mathar, Jul 24 2009
STATUS
approved