A258776 Primes in A258774.

3, 13, 43, 157, 73, 241, 157, 211, 601, 601, 421, 601, 2971, 1483, 8191, 6163, 3307, 2971, 6481, 8191, 28393, 3907, 28393, 6481, 8191, 28393, 37057, 26407, 12211, 28393, 31153, 113233, 19183, 83233, 113233, 37057, 28393, 71023, 22651, 83233, 37057, 154057

Offset: 1

Author

Robert Price, Jun 09 2015

Keywords

• nonn

Comments

These primes are neither sorted nor uniqued. They are listed in the order found in A258774.

Links

• Robert Price, Table of n, a(n) for n = 1..2122
• OEIS Wiki, Cyclotomic Polynomials at x=n, n! and sigma(n)

Crossrefs

Cf. A000203, A258774, A258775.

Programs

Magma

[a: n in [1..300] | IsPrime(a) where a is 1+SumOfDivisors(n)+ SumOfDivisors(n)^2]; // Vincenzo Librandi, Jun 10 2015

Mathematica

Select[Table[1 + DivisorSigma[1, n] + DivisorSigma[1, n]^2, {n, 1, 10000}], PrimeQ]
Select[Table[Cyclotomic[3, DivisorSigma[1, n]], {n, 1, 10000}], PrimeQ]

Formula

a(n) = A258774(A258775(n)).