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%I #21 May 09 2021 02:50:50
%S 1,17,730,65553,9765626,2176783082,678223072850,281474976776209,
%T 150094635296999851,100000000000009765642,81402749386839761113322,
%U 79496847203390846310290154,91733330193268616658399616010,123476695691247935826908004929122
%N a(n) = Sum_{d|n} d^(2*d).
%H Seiichi Manyama, <a href="/A308696/b308696.txt">Table of n, a(n) for n = 1..214</a>
%F L.g.f.: -log(Product_{k>=1} (1 - x^k)^(k^(2*k-1))) = Sum_{k>=1} a(k)*x^k/k.
%F G.f.: Sum_{k>=1} k^(2*k) * x^k/(1 - x^k).
%t a[n_] := DivisorSum[n, #^(2*#) &]; Array[a, 14] (* _Amiram Eldar_, May 09 2021 *)
%o (PARI) {a(n) = sumdiv(n, d, d^(2*d))}
%o (PARI) N=20; x='x+O('x^N); Vec(x*deriv(-log(prod(k=1, N, (1-x^k)^k^(2*k-1)))))
%o (PARI) N=20; x='x+O('x^N); Vec(sum(k=1, N, k^(2*k)*x^k/(1-x^k)))
%Y Column k=2 of A308698.
%Y Cf. A073705, A308753, A308756.
%K nonn
%O 1,2
%A _Seiichi Manyama_, Jun 17 2019
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