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A341036
a(n) = Sum_{k=1..n} gcd(k,n)^(k-2).
2
1, 2, 5, 19, 129, 1306, 16813, 262181, 4783059, 100000214, 2357947701, 61917372083, 1792160394049, 56693912393474, 1946195068811453, 72057594039243049, 2862423051509815809, 121439531096661117354, 5480386857784802185957
OFFSET
1,2
MATHEMATICA
a[n_] := Sum[GCD[k, n]^(k - 2), {k, 1, n}]; Array[a, 20] (* Amiram Eldar, Mar 13 2021 *)
PROG
(PARI) a(n) = sum(k=1, n, gcd(k, n)^(k-2));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Mar 13 2021
STATUS
approved