A089124 - OEIS

%I #10 Aug 25 2024 16:18:16

%S 2,7,3,19,7,13,13,67,7,103,31,7,43,199,19,37,73,109,13,31,37,487,19,

%T 193,157,97,61,787,211,43,241,79,13,61,307,433,7,1447,127,229,421,31,

%U 463,277,13,163,79,769,601,2503,31,2707,37,139,757,73,271,37,67,1201,19

%N Largest prime factor of n^2 + 3.

%D H. Rademacher, Lectures on Elementary Number Theory, pp. 33-38.

%H Harvey P. Dale, <a href="/A089124/b089124.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = A006530(A117950(n)). - _Jason Yuen_, Aug 25 2024

%t FactorInteger[#][[-1,1]]&/@(Range[70]^2+3) (* _Harvey P. Dale_, Jun 17 2020 *)

%o (PARI) largeasqp3(m) = { for(a=1,m, y=a^2 + 3; f = factor(y); v = component(f,1); v1 = v[length(v)]; print1(v1",")) }

%Y Cf. A049423, A006530, A117950.

%K easy,nonn

%O 1,1

%A _Cino Hilliard_, Dec 05 2003