OFFSET
1,2
COMMENTS
Or, numbers j arising in A137530.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
FORMULA
a(n) = sqrt((A137530(n) - 1)/180).
MATHEMATICA
Select[Range[250], PrimeQ[180#^2+1]&] (* Harvey P. Dale, May 26 2024 *)
PROG
(Magma) [n: n in [0..10000]|IsPrime(1+180*n^2)] // Vincenzo Librandi, Dec 13 2010
(PARI) is(n)=isprime(1+180*n^2) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Zak Seidov, May 05 2008
STATUS
approved