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

1,1

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)

Formula

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

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]

Prog

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

Crossrefs

Cf. A000203, A258774, A258775.

Sequence in context: A049173 A049156 A054771 * A201710 A019008 A062609

Adjacent sequences: A258773 A258774 A258775 * A258777 A258778 A258779

Keyword

nonn

Author

Robert Price, Jun 09 2015

Status

approved