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a(n) = Sum_{i=1..n} gcd(n^(n-i),n-i).
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%I #7 Apr 16 2021 10:04:15

%S 1,2,3,5,5,12,7,13,13,26,11,39,13,36,37,33,17,74,19,69,57,68,23,103,

%T 41,82,55,97,29,226,31,81,109,130,103,207,37,140,129,193,41,324,43,

%U 177,183,164,47,281,85,266,163,213,53,340,175,287,201,210,59,621,61,220,289

%N a(n) = Sum_{i=1..n} gcd(n^(n-i),n-i).

%t Table[Sum[GCD[n^(n - i), n - i], {i, n}], {n, 100}]

%o (PARI) a(n) = sum(i=1, n, gcd(n^(n-i), n-i)); \\ _Michel Marcus_, Apr 15 2021

%Y Cf. A018804 (Pillai's function), A342449, A343114.

%K nonn

%O 1,2

%A _Wesley Ivan Hurt_, Apr 13 2021