A259410 a(n) = 1 - sigma(n) + sigma(n)^2 - sigma(n)^3 + sigma(n)^4.
1, 61, 205, 2101, 1111, 19141, 3641, 47461, 26521, 99451, 19141, 593461, 35855, 318505, 318505, 894661, 99451, 2255605, 152381, 3039331, 1016801, 1634221, 318505, 12747541, 894661, 3039331, 2497561, 9661961, 783871, 26505721, 1016801, 15506821, 5200081
Offset: 1
Links
- Robert Price, Table of n, a(n) for n = 1..10000
- OEIS Wiki, Cyclotomic Polynomials at x=n, n! and sigma(n)
Crossrefs
Programs
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Magma
[(1 - DivisorSigma(1, n) + DivisorSigma(1, n)^2 - DivisorSigma(1, n)^3 + DivisorSigma(1, n)^4): n in [1..35]]; // Vincenzo Librandi, Jun 27 2015
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Mathematica
Table[1 - DivisorSigma[1, n] + DivisorSigma[1, n]^2 - DivisorSigma[1, n]^3 + DivisorSigma[1, n]^4, {n, 1, 10000}] Table[Cyclotomic[10, DivisorSigma[1, n]], {n, 1, 10000}]
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PARI
a(n) = polcyclo(10, sigma(n)) \\ Michel Marcus, Jun 26 2015
Comments