This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A258776 #19 Sep 08 2022 08:46:12
%S A258776 3,13,43,157,73,241,157,211,601,601,421,601,2971,1483,8191,6163,3307,
%T A258776 2971,6481,8191,28393,3907,28393,6481,8191,28393,37057,26407,12211,
%U A258776 28393,31153,113233,19183,83233,113233,37057,28393,71023,22651,83233,37057,154057
%N A258776 Primes in A258774.
%C A258776 These primes are neither sorted nor uniqued. They are listed in the order found in A258774.
%H A258776 Robert Price, <a href="/A258776/b258776.txt">Table of n, a(n) for n = 1..2122</a>
%H A258776 OEIS Wiki, <a href="https://oeis.org/wiki/Cyclotomic Polynomials at x=n, n! and sigma(n)">Cyclotomic Polynomials at x=n, n! and sigma(n)</a>
%F A258776 a(n) = A258774(A258775(n)).
%t A258776 Select[Table[1 + DivisorSigma[1, n] + DivisorSigma[1, n]^2, {n, 1, 10000}], PrimeQ]
%t A258776 Select[Table[Cyclotomic[3, DivisorSigma[1, n]], {n, 1, 10000}], PrimeQ]
%o A258776 (Magma) [a: n in [1..300] | IsPrime(a) where a is 1+SumOfDivisors(n)+ SumOfDivisors(n)^2]; // _Vincenzo Librandi_, Jun 10 2015
%Y A258776 Cf. A000203, A258774, A258775.
%K A258776 nonn
%O A258776 1,1
%A A258776 _Robert Price_, Jun 09 2015