cp's OEIS Frontend

A259369 a(n) = 1 + sigma(n)^3 + sigma(n)^6.

%I A259369 #17 Sep 08 2022 08:46:13
%S A259369 3,757,4161,117993,46873,2987713,262657,11394001,4829007,34018057,
%T A259369 2987713,481912257,7532281,191116801,191116801,887533473,34018057,
%U A259369 3518803081,64008001,5489105833,1073774593,2176828993,191116801,46656216001,887533473,5489105833
%N A259369 a(n) = 1 + sigma(n)^3 + sigma(n)^6.
%H A259369 Robert Price, <a href="/A259369/b259369.txt">Table of n, a(n) for n = 1..10000</a>
%H A259369 OEIS Wiki, <a href="https://oeis.org/wiki/Cyclotomic Polynomials at x=n, n! and sigma(n)">Cyclotomic Polynomials at x=n, n! and sigma(n)</a>
%F A259369 a(n) = 1 + A000203(n)^3 + A000203(n)^6.
%F A259369 a(n) = A060883(A000203(n)). - _Michel Marcus_, Jun 25 2015
%p A259369 with(numtheory): A259369:=n->1+sigma(n)^3+sigma(n)^6: seq(A259369(n), n=1..40); # _Wesley Ivan Hurt_, Jun 29 2015
%t A259369 Table[1 + DivisorSigma[1, n]^3 + DivisorSigma[1, n]^6, {n, 10000}]
%t A259369 Table[Cyclotomic[9, DivisorSigma[1, n]], {n, 10000}]
%o A259369 (PARI) a(n) = polcyclo(9, sigma(n)) \\ _Michel Marcus_, Jun 25 2015
%o A259369 (Magma) [1+SumOfDivisors(n)^3+ SumOfDivisors(n)^6: n in [1..50]]; // _Vincenzo Librandi_, Jun 26 2015
%Y A259369 Cf. A000203 (sum of divisors of n), A060883 (n^6 + n^3 + 1).
%Y A259369 Cf. A259370 (indices of primes in this sequence), A259371 (corresponding primes).
%K A259369 easy,nonn
%O A259369 1,1
%A A259369 _Robert Price_, Jun 25 2015