A258980 Primes in A258978.

5, 2801, 22621, 30941, 22621, 637421, 346201, 346201, 346201, 2625641, 837931, 16007041, 3835261, 209102521, 209102521, 15018571, 262209281, 21700501, 30397351, 209102521, 209102521, 693025471, 147753211, 4244897281, 1740422941, 6903678241, 2439903211

Offset: 1

Author

Robert Price, Jun 15 2015

Keywords

• nonn

Comments

These primes are neither sorted nor uniqued. They are listed in the order found in A258978.

Links

• Robert Price, Table of n, a(n) for n = 1..932
• OEIS Wiki, Cyclotomic Polynomials at x=n, n! and sigma(n)

Crossrefs

Cf. A000203, A258978, A258979.

Programs

Magma

[m: n in [1..200] | IsPrime(m) where m is (1 + DivisorSigma(1, n) + DivisorSigma(1, n)^2 + DivisorSigma(1, n)^3 + DivisorSigma(1, n)^4)]; // Vincenzo Librandi, Jun 16 2015

Maple

with(numtheory): A258980:=n->`if`(isprime(1 + sigma(n) + sigma(n)^2 + sigma(n)^3 + sigma(n)^4), 1 + sigma(n) + sigma(n)^2 + sigma(n)^3 + sigma(n)^4, NULL): seq(A258980(n), n=1..300); # Wesley Ivan Hurt, Jul 09 2015

Mathematica

Select[Table[1 + DivisorSigma[1, n] + DivisorSigma[1, n]^2 + DivisorSigma[1, n]^3 + DivisorSigma[1, n]^4, {n, 10000}], PrimeQ]
Select[Table[Cyclotomic[5, DivisorSigma[1, n]], {n, 10000}], PrimeQ]

Formula

a(n) = A258978(A258979(n)).