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%I #11 Sep 23 2020 02:47:58
%S 9,54,162,567,1458,4860,13122,40824,118827,358668,1062882,3206142,
%T 9565938,28737180,86106564,258404985,774840978,2324916594,6973568802,
%U 20921808654,62762237316,188289546300,564859072962,1694587257216
%N Dirichlet convolution of powers of 3 (3,9,27,...) with themselves.
%F a(n) ~ 2 * 3^(n+1). - _Vaclav Kotesovec_, Sep 11 2019
%F G.f.: Sum_{k>=1} 3^(k+1)*x^k / (1 - 3*x^k). - _Ilya Gutkovskiy_, Sep 22 2020
%t Table[Sum[3^(d + n/d), {d, Divisors[n]}], {n, 1, 30}] (* _Vaclav Kotesovec_, Sep 11 2019 *)
%Y Equals 9 * A034751(n).
%K nonn
%O 1,1
%A _Erich Friedman_
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