A347251 a(n) = Sum_{d|n} mu(d)*mu(n/d)*d^n.
1, -5, -28, 16, -3126, 47450, -823544, 0, 19683, 10009766650, -285311670612, -2176786432, -302875106592254, 11112685048647250, 437893920912786408, 0, -827240261886336764178, -101560344088905, -1978419655660313589123980, -100000000000001048576
Offset: 1
Keywords
Links
- Seiichi Manyama, Table of n, a(n) for n = 1..388
Programs
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Mathematica
a[n_] := DivisorSum[n, MoebiusMu[#] * MoebiusMu[n/#] * #^n &]; Array[a, 20] (* Amiram Eldar, Aug 24 2021 *)
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PARI
a(n) = sumdiv(n, d, moebius(d)*moebius(n/d)*d^n);
Formula
If p is prime, a(p) = -1 - p^p.