A309844 - OEIS

%I #20 Sep 28 2019 22:37:02

%S 3,5,23,653,10103,83813,160403,234743,280373,1049603,3420653,6252503,

%T 11319863,52207853,92246423,146422103,174913853,221548343,442071653,

%U 479807123,577224653,607597853,655385603,937921253,1222865933,1249233683,1387525253,1506177293

%N Primes of the form n^4 + n^2 + 3.

%C Digital root of all values > 3 is 5, compare A017221.

%t f[n_] := n^4 + n^2 + 3; Select[f /@ Range[0, 200], PrimeQ] (* _Amiram Eldar_, Aug 24 2019 *)

%o (MATLAB)

%o a = [];

%o for n = 0:1e3

%o     x = n.^4+n.^2+3;

%o     if isprime(x); a = [a,x]; end;

%o end

%o (Python)

%o from sympy import isprime

%o a = []

%o for n in range(0,1000):

%o     x = n**4+n**2+3

%o     if isprime(x):

%o         a.append(x)

%Y Subset of A027753. Subset of A017221.

%Y Cf. A037896, A182344, A182345, A049423.

%K nonn,easy

%O 1,1

%A _Christopher R. Madan_, Aug 19 2019