|
%I #13 Mar 13 2021 10:05:13
%S 1,3,5,10,9,33,13,60,69,167,21,470,25,837,1245,1624,33,5067,37,9570,
%T 13841,20633,45,54612,12545,98511,119601,201646,57,562957,61,794928,
%U 1774185,2097491,536037,5381754,73,9437601,19136333,14296940
%N a(n) = Sum_{k=1..n} gcd(k,n)^(n/gcd(k,n)).
%H Seiichi Manyama, <a href="/A342424/b342424.txt">Table of n, a(n) for n = 1..5000</a>
%F a(n) = Sum_{d|n} phi(n/d) * d^(n/d).
%t a[n_] := Sum[GCD[k, n]^(n/GCD[k, n]), {k, 1, n}]; Array[a, 40] (* _Amiram Eldar_, Mar 11 2021 *)
%o (PARI) a(n) = sum(k=1, n, gcd(k, n)^(n/gcd(k, n)));
%o (PARI) a(n) = sumdiv(n, d, eulerphi(n/d)*d^(n/d));
%Y Cf. A000010, A332517, A342423.
%K nonn
%O 1,2
%A _Seiichi Manyama_, Mar 11 2021
|
