A259308 a(n) = 1 + sigma(n)^4.

2, 82, 257, 2402, 1297, 20737, 4097, 50626, 28562, 104977, 20737, 614657, 38417, 331777, 331777, 923522, 104977, 2313442, 160001, 3111697, 1048577, 1679617, 331777, 12960001, 923522, 3111697, 2560001, 9834497, 810001, 26873857, 1048577, 15752962, 5308417

Offset

1,1

Links

Robert Price, Table of n, a(n) for n = 1..10000

OEIS Wiki, Cyclotomic Polynomials at x=n, n! and sigma(n)

Formula

a(n) = 1 + A000203(n)^4.

a(n) = A019326(A000203(n)). - Michel Marcus, Jun 24 2015

Maple

with(numtheory): A259308:=n->1+sigma(n)^4: seq(A259308(n), n=1..50); # Wesley Ivan Hurt, Jul 09 2015

Mathematica

Table[1 + DivisorSigma[1, n]^4, {n, 10000}]
Table[Cyclotomic[8, DivisorSigma[1, n]], {n, 10000}]

Prog

(Magma) [(1 + SumOfDivisors(n)^4): n in [1..50]]; // Vincenzo Librandi, Jun 24 2015

Crossrefs

Cf. A000203 (sum of divisors of n).

Cf. A259309 (indices of primes in this sequence), A259310 (corresponding primes).

Sequence in context: A230398 A120826 A343588 * A202965 A307583 A061994

Adjacent sequences: A259305 A259306 A259307 * A259309 A259310 A259311

Keyword

easy,nonn

Author

Robert Price, Jun 24 2015

Status

approved