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A258776 Primes in A258774. 4
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified December 5 09:43 EST 2022. Contains 358585 sequences. (Running on oeis4.)